prep.[ AS. uppan, uppon; upp up + on, an, on. See Up, and On. ] On; -- used in all the senses of that word, with which it is interchangeable. “Upon an hill of flowers.” Chaucer. [ 1913 Webster ]

Our host upon his stirrups stood anon. Chaucer. [ 1913 Webster ]

Thou shalt take of the blood that is upon the altar. Ex. xxix. 21. [ 1913 Webster ]

The Philistines be upon thee, Samson. Judg. xvi. 9. [ 1913 Webster ]

As I did stand my watch upon the hill. Shak. [ 1913 Webster ]

He made a great difference between people that did rebel upon wantonness, and them that did rebel upon want. Bacon. [ 1913 Webster ]

This advantage we lost upon the invention of firearms. Addison. [ 1913 Webster ]

Upon the whole, it will be necessary to avoid that perpetual repetition of the same epithets which we find in Homer. Pope. [ 1913 Webster ]

He had abandoned the frontiers, retiring upon Glasgow. Sir. W. Scott. [ 1913 Webster ]

Philip swore upon the Evangelists to abstain from aggression in my absence. Landor. [ 1913 Webster ]

☞ Upon conveys a more distinct notion that on carries with it of something that literally or metaphorically bears or supports. It is less employed than it used to be, on having for the most part taken its place. Some expressions formed with it belong only to old style; as, upon pity they were taken away; that is, in consequence of pity: upon the rate of thirty thousand; that is, amounting to the rate: to die upon the hand; that is, by means of the hand: he had a garment upon; that is, upon himself: the time is coming fast upon; that is, upon the present time. By the omission of its object, upon acquires an adverbial sense, as in the last two examples. [ 1913 Webster ]

To assure upon (Law), to promise; to undertake. --
To come upon. See under Come. --
To take upon, to assume. [ 1913 Webster ]