n. (Chem.) The quality or state of being univalent. [ 1913 Webster ]

a. [ Uni- + L. valens, -entis, p. pr. See Valence. ] (Chem.) Having a valence of one; capable of combining with, or of being substituted for, one atom of hydrogen; monovalent; -- said of certain atoms and radicals. [ 1913 Webster ]

n. [ Uni- + valve: cf. F. univalve. ] (Zool.) A shell consisting of one valve only; a mollusk whose shell is composed of a single piece, as the snails and conchs. [ 1913 Webster ]

☞ Most univalves are spiral and are the shells of gastropods, but many belong to cephalopods and pteropods. A large number of univalves belonging to the gastropods are conical, cup-shaped, or shieldlike, as the limpets. [ 1913 Webster ]

{ } a. [ Cf. F. univalve. ] (Bot. & Zool.) Having one valve; as, a univalve shell or pericarp. [ 1913 Webster ]

‖n. pl. [ NL. ] (Zool.) Same as Gastropoda. [ 1913 Webster ]

a. (Bot. & Zool.) Same as Univalve, a. [ 1913 Webster ]

a. (Chem.) Having one degree of freedom or variability. [ Webster 1913 Suppl. ]

n. 1. The whole; the general system of the universe; the universe. [ Obs. ] [ 1913 Webster ]

Plato calleth God the cause and original, the nature and reason, of the universal. Sir W. Raleigh. [ 1913 Webster ]

2. (Logic) (a) A general abstract conception, so called from being universally applicable to, or predicable of, each individual or species contained under it. (b) A universal proposition. See Universal, a., 4. [ 1913 Webster ]

a. [ L. universalis: cf. F. universel, OF. also universal. See Universe. ] 1. Of or pertaining to the universe; extending to, including, or affecting, the whole number, quantity, or space; unlimited; general; all-reaching; all-pervading; as, universal ruin; universal good; universal benevolence or benefice. “Anointed universal King.” Milton. [ 1913 Webster ]

The universal cause
Acts not by partial, but by general laws. Pope. [ 1913 Webster ]

This universal frame began. Dryden. [ 1913 Webster ]

☞ Universal and its derivatives are used in common discourse for general and its derivatives. See General. [ 1913 Webster ]

2. Constituting or considered as a whole; total; entire; whole; as, the universal world. Shak. [ 1913 Webster ]

At which the universal host up dent
A shout that tore Hell's concave. Milton. [ 1913 Webster ]

3. (Mech.) Adapted or adaptable to all or to various uses, shapes, sizes, etc.; as, a universal milling machine. [ 1913 Webster ]

4. (Logic) Forming the whole of a genus; relatively unlimited in extension; affirmed or denied of the whole of a subject; as, a universal proposition; -- opposed to particular; e. g. (universal affirmative) All men are animals; (universal negative) No men are omniscient. [ 1913 Webster ]

Universal chuck (Mach.), a chuck, as for a lathe, having jaws which can be moved simultaneously so as to grasp objects of various sizes. --
Universal church, the whole church of God in the world; the catholic church. See the Note under Catholic, a., 1. --
Universal coupling. (Mach.) Same as Universal joint, below. --
Universal dial, a dial by which the hour may be found in any part of the world, or under any elevation of the pole. --
Universal instrument (Astron.), a species of altitude and azimuth instrument, the peculiarity of which is, that the object end of the telescope is placed at right angles to the eye end, with a prism of total reflection at the angle, and the eye end constitutes a portion of the horizontal axis of the instrument, having the eyepiece at the pivot and in the center of the altitude circle, so that the eye has convenient access to both at the same time. --
Universal joint (Mach.), a contrivance used for joining two shafts or parts of a machine endwise, so that the one may give rotary motion to the other when forming an angle with it, or may move freely in all directions with respect to the other, as by means of a cross connecting the forked ends of the two shafts (Fig. 1). Since this joint can not act when the angle of the shafts is less than 140°, a double joint of the same kind is sometimes used for giving rotary motion at angles less than 140° (Fig. 2). --
Universal umbel (Bot.), a primary or general umbel; the first or largest set of rays in a compound umbel; -- opposed to partial umbel. A universal involucre is not unfrequently placed at the foot of a universal umbel. [ 1913 Webster ]

Syn. -- General; all; whole; total. See General. [ 1913 Webster ]

n. (Med.) a person belonging to the O blood group (of the ABO classification), who can safely donate blood to anyone. [ PJC ]