The Collaborative International Dictionary of English v.0.48:

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.
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   2. To sour; to imbitter.
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            His thin existence all acidified into rage.
                                                  --Carlyle.
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