Acidify \A*cid"i*fy\, v. t. [imp. & p. p. {Acidified}; p. pr. & vb. n. {Acidifying}.] [L. acidus sour, acid + -fy: cf. F. acidifier.] 1. To make acid; to convert into an acid; as, to acidify sugar. 2. To sour; to imbitter. His thin existence all acidified into rage. --Carlyle.