Buy  —v. (buys, buying; past and past part. Bought) 1 a obtain for money etc. B serve to obtain (money can't buy happiness; the best that money can buy). 2 a procure by bribery etc. B bribe. 3 get by sacrifice etc. 4 slang believe in, accept. 5 be a buyer for a store etc. —n. Colloq. Purchase.  buy in buy a stock of. Buy into pay for a share in (an enterprise). Buy off pay to get rid of. Buy oneself out obtain one's release (esp. From the armed services) by payment. Buy out pay (a person) for ownership, an interest, etc. Buy up 1 buy as much as possible of. 2 absorb (a firm etc.) By purchase. [old english]