1911 Encyclopædia Britannica/Purchase

PURCHASE, in its common sense, that which is acquired by the payment of money or its equivalent. The original meaning of the word (O. Fr. pourchacier, pourchasser, &c., popular, Lat. pro-captiare) was to pursue eagerly, hence to acquire. Thus “purchase” was early used by the lawyers (e.g. Britton, in 1292) for the acquirement of property by other means than inheritance or mere act of law, including acquirement by escheat, prescription, occupancy, alienation and forfeiture; more generally, purchase in law means acquisition of land by bargain or sale, according to the law of “vendor and purchaser” (see Conveyancing). A later development of meaning is found in the use of the word for a mechanical contrivance by which power can be excited or applied, a hold or fulcrum. This first appears (16th century) in the nautical use of the verb, to haul up a rope or cable by some mechanical device, the root idea being apparently to “gain” advantage over the rope bit by bit.