2. Behind; in the rear. Knolles. [ 1913 Webster ]

3. (Naut.) Backward against the mast; -- said of the sails when pressed by the wind. Totten. [ 1913 Webster ]

To be taken aback. (a) To be driven backward against the mast; -- said of the sails, also of the ship when the sails are thus driven. (b) To be suddenly checked, baffled, or discomfited. Dickens. [ 1913 Webster ]

Two suspicious fellows ahorseback. Smollet. [ 1913 Webster ]

2. (Naut.) To change from one quarter to another by a course opposite to that of the sun; -- used of the wind. [ 1913 Webster ]

3. (Sporting) To stand still behind another dog which has pointed; -- said of a dog. [ Eng. ] [ 1913 Webster ]

To back and fill, to manage the sails of a ship so that the wind strikes them alternately in front and behind, in order to keep the ship in the middle of a river or channel while the current or tide carries the vessel against the wind. Hence: (Fig.) To take opposite positions alternately; to assert and deny. [ Colloq. ] --
To back out,
To back down, to retreat or withdraw from a promise, engagement, or contest; to recede. [ Colloq. ] [ 1913 Webster ]

Cleon at first . . . was willing to go; but, finding that he [ Nicias ] was in earnest, he tried to back out. Jowett (Thucyd. ) [ 1913 Webster ]

2. Being in arrear; overdue; as, back rent. [ 1913 Webster ]

3. Moving or operating backward; as, back action. [ 1913 Webster ]

Back blocks, Australian pastoral country which is remote from the seacoast or from a river. [ Webster 1913 Suppl. ] --
Back charges, charges brought forward after an account has been made up. --
Back filling (Arch.), the mass of materials used in filling up the space between two walls, or between the inner and outer faces of a wall, or upon the haunches of an arch or vault. --
Back pressure. (Steam Engine) See under Pressure. --
Back rest, a guide attached to the slide rest of a lathe, and placed in contact with the work, to steady it in turning. --
Back slang, a kind of slang in which every word is written or pronounced backwards; as, nam for man. --
Back stairs, stairs in the back part of a house; private stairs. Also used adjectively. See Back stairs, Backstairs, and Backstair, in the Vocabulary. --
Back step (Mil.), the retrograde movement of a man or body of men, without changing front. --
Back stream, a current running against the main current of a stream; an eddy. --
To take the back track, to retrace one's steps; to retreat. [ Colloq. ] [ 1913 Webster ]

1. To get upon the back of; to mount. [ 1913 Webster ]

I will back him [ a horse ] straight. Shak. [ 1913 Webster ]

2. To place or seat upon the back. [ R. ] [ 1913 Webster ]

Great Jupiter, upon his eagle backed,
Appeared to me. Shak. [ 1913 Webster ]

3. To drive or force backward; to cause to retreat or recede; as, to back oxen. [ 1913 Webster ]

4. To make a back for; to furnish with a back; as, to back books. [ 1913 Webster ]

5. To adjoin behind; to be at the back of. [ 1913 Webster ]

A garden . . . with a vineyard backed. Shak. [ 1913 Webster ]

The chalk cliffs which back the beach. Huxley. [ 1913 Webster ]

6. To write upon the back of; as, to back a letter; to indorse; as, to back a note or legal document. [ 1913 Webster ]

7. To support; to maintain; to second or strengthen by aid or influence; as, to back a friend. “The Parliament would be backed by the people.” Macaulay. [ 1913 Webster ]

Have still found it necessary to back and fortify their laws with rewards and punishments. South. [ 1913 Webster ]

The mate backed the captain manfully. Blackw. Mag. [ 1913 Webster ]

8. To bet on the success of; -- as, to back a race horse. [ 1913 Webster ]

To back an anchor (Naut.), to lay down a small anchor ahead of a large one, the cable of the small one being fastened to the crown of the large one. --
To back the field, in horse racing, to bet against a particular horse or horses, that some one of all the other horses, collectively designated “the field”, will win. --
To back the oars, to row backward with the oars. --
To back a rope, to put on a preventer. --
To back the sails, to arrange them so as to cause the ship to move astern. --
To back up, to support; to sustain; as, to back up one's friends. --
To back a warrant (Law), is for a justice of the peace, in the county where the warrant is to be executed, to sign or indorse a warrant, issued in another county, to apprehend an offender. --
To back water (Naut.), to reverse the action of the oars, paddles, or propeller, so as to force the boat or ship backward. [ 1913 Webster ]

2. To the place from which one came; to the place or person from which something is taken or derived; as, to go back for something left behind; to go back to one's native place; to put a book back after reading it. [ 1913 Webster ]

3. To a former state, condition, or station; as, to go back to private life; to go back to barbarism. [ 1913 Webster ]

4. (Of time) In times past; ago. “Sixty or seventy years back.” Gladstone. [ 1913 Webster ]

5. Away from contact; by reverse movement. [ 1913 Webster ]

The angel of the Lord . . . came, and rolled back the stone from the door. Matt. xxviii. 2. [ 1913 Webster ]

6. In concealment or reserve; in one's own possession; as, to keep back the truth; to keep back part of the money due to another. [ 1913 Webster ]

7. In a state of restraint or hindrance. [ 1913 Webster ]

The Lord hath kept thee back from honor. Numb. xxiv. 11. [ 1913 Webster ]

8. In return, repayment, or requital. [ 1913 Webster ]

What have I to give you back? Shak. [ 1913 Webster ]

9. In withdrawal from a statement, promise, or undertaking; as, he took back the offensive words. [ 1913 Webster ]

10. In arrear; as, to be back in one's rent. [ Colloq. ] [ 1913 Webster ]

Back and forth, backwards and forwards; to and fro. --
To go back on, to turn back from; to abandon; to betray; as, to go back on a friend; to go back on one's professions. [ Colloq. ] [ 1913 Webster ]

Hop back,
Jack back, the cistern which receives the infusion of malt and hops from the copper. --
Wash back, a vat in which distillers ferment the wort to form wash. --
Water back, a cistern to hold a supply of water; esp. a small cistern at the back of a stove, or a group of pipes set in the fire box of a stove or furnace, through which water circulates and is heated. [ 1913 Webster ]

2. A ferryboat. See Bac, 1. [ 1913 Webster ]

2. An extended upper part, as of a mountain or ridge. [ 1913 Webster ]

[ The mountains ] their broad bare backs upheave
Into the clouds. Milton. [ 1913 Webster ]

3. The outward or upper part of a thing, as opposed to the inner or lower part; as, the back of the hand, the back of the foot, the back of a hand rail. [ 1913 Webster ]

Methought Love pitying me, when he saw this,
Gave me your hands, the backs and palms to kiss. Donne. [ 1913 Webster ]

4. The part opposed to the front; the hinder or rear part of a thing; as, the back of a book; the back of an army; the back of a chimney. [ 1913 Webster ]

5. The part opposite to, or most remote from, that which fronts the speaker or actor; or the part out of sight, or not generally seen; as, the back of an island, of a hill, or of a village. [ 1913 Webster ]

6. The part of a cutting tool on the opposite side from its edge; as, the back of a knife, or of a saw. [ 1913 Webster ]

7. A support or resource in reserve. [ 1913 Webster ]

This project
Should have a back or second, that might hold,
If this should blast in proof. Shak. [ 1913 Webster ]

8. (Naut.) The keel and keelson of a ship. [ 1913 Webster ]

9. (Mining) The upper part of a lode, or the roof of a horizontal underground passage. [ 1913 Webster ]

10. A garment for the back; hence, clothing. [ Obs. ] [ 1913 Webster ]

A bak to walken inne by daylight. Chaucer. [ 1913 Webster ]

Behind one's back, when one is absent; without one's knowledge; as, to ridicule a person behind his back. --
Full back,
Half back,
Quarter back (Football), players stationed behind those in the front line. --
To be on one's back or
To lie on one's back, to be helpless. --
To put one's back up or
to get one's back up, to assume an attitude of obstinate resistance (from the action of a cat when attacked). [ Colloq. ] --
To see the back of, to get rid of. --
To turn the back, to go away; to flee. --
To turn the back on one, to forsake or neglect him. [ 1913 Webster ]

They are arrant knaves, and will backbite. Shak. [ 1913 Webster ]

Backbiting, and bearing of false witness. Piers Plowman. [ 1913 Webster ]

1. A board which supports the back when one is sitting; specifically, the board athwart the after part of a boat. [ 1913 Webster ]

2. A board serving as the back part of anything, as of a wagon. [ 1913 Webster ]

3. A thin stuff used for the backs of framed pictures, mirrors, etc. [ 1913 Webster ]

4. A board attached to the rim of a water wheel to prevent the water from running off the floats or paddles into the interior of the wheel. W. Nicholson. [ 1913 Webster ]

5. A board worn across the back to give erectness to the figure. Thackeray. [ 1913 Webster ]

1. The column of bones in the back which sustains and gives firmness to the frame; the spine; the vertebral or spinal column. [ 1913 Webster ]

2. Anything like , or serving the purpose of, a backbone. [ 1913 Webster ]

The lofty mountains on the north side compose the granitic axis, or backbone of the country. Darwin. [ 1913 Webster ]

We have now come to the backbone of our subject. Earle. [ 1913 Webster ]

3. Firmness; moral principle; steadfastness. [ 1913 Webster ]

Shelley's thought never had any backbone. Shairp. [ 1913 Webster ]

To the backbone, through and through; thoroughly; entirely. “Staunch to the backbone.” Lord Lytton. [ 1913 Webster ]

2. to affix a date earlier than the present date; -- sometimes done for fraudulent purposes. Opposite of postdate.
Syn. -- back-date; predate; antedate. [ PJC ]

Backdate is sometimes used incorrectly for postdate.

2. the background, setting, or circumstances of an event; as, the backdrop for the summit meeting. [ PJC ]

2. Of a Bunsen or similar air-fed burner, to light so that the flame proceeds from the internal gas jet instead of from the external jet of mixed gas and air. -- Back"-fir`ing, n. [Webster 1913 Suppl.]

2. (a) A premature explosion in the cylinder of a gas or oil engine during the exhaust or the compression stroke, tending to drive the piston in a direction reverse to that in which it should travel; also called a knock or ping. (b) an explosion in the exhaust passages of an internal combustion engine. [ Webster 1913 Suppl. +PJC ]

2. the process of inventing a back-formation{ 1 }. [ PJC ]

backgammon board, a board for playing backgammon, often made in the form of two rectangular trays hinged together, each tray containing two “tables”. [ 1913 Webster ]

1. Ground in the rear or behind, or in the distance, as opposed to the foreground, or the ground in front. [ 1913 Webster ]

2. (Paint.) The space which is behind and subordinate to a portrait or group of figures. [ 1913 Webster ]

☞ The distance in a picture is usually divided into foreground, middle distance, and background. Fairholt. [ 1913 Webster ]

3. Anything behind, serving as a foil; as, the statue had a background of red hangings. [ 1913 Webster ]

4. A place in obscurity or retirement, or out of sight. [ 1913 Webster ]

I fancy there was a background of grinding and waiting before Miss Torry could produce this highly finished . . . performance. Mrs. Alexander. [ 1913 Webster ]

A husband somewhere in the background. Thackeray. [ 1913 Webster ]

5. The set of conditions within which an action takes place, including the social and physical conditions as well as the psychological states of the participants; as, within the background of the massive budget deficits of the 1980's, new spending programs had little chance of passage by the congress. [ PJC ]

6. The set of conditions that precede and affect an action, such as the social and historical precedents for the event, as well as the general background{ 5 }; as, against the background of their expulsion by the Serbs, the desire of Kosovars for vengeance is understandable though regrettable. [ PJC ]

7. (Science) The signals that may be detected by a measurement which are not due to the phenomenon being studied, and tend to make the measurement uncertain to a greater or lesser degree. Specifically: (Physics) Electronic noise present in a system using electronic measuring instrument or in a telecommunications system, which may hide and which must be differentiated from the desired signal; also called background noise or noise. [ PJC ]

8. (Journalism) An agreement between a journalist and an interviewee that the name of the interviewee will not be quoted in any publication, although the substance of the remarks may be reported; -- often used in the phrase “on background”. Compare deep background. [ PJC ]

To place in the background, to make of little consequence.
To keep in the background, to remain unobtrusive, inconspicuous or out of sight; -- of people.
deep background, (Journalism) the status of an interview which must not be quoted in a publication, even without attribution. Compare background{ 8 }. [ 1913 Webster +PJC ]

2. (Sports) The stroke of a ball with a racket or paddle, in which head of the racket starts from the side of the body opposite to that of the arm in which the racket is held, and proceeds forward to meet the ball. Contrasted with forehand. [ PJC ]

2. Backhanded; indirect; oblique. [ R. ] [ 1913 Webster ]

2. Indirect; awkward; insincere; sarcastic; as, a backhanded compliment. [ 1913 Webster ]

3. Turned back, or inclining to the left; as, backhanded letters. [ 1913 Webster ]