'acidify' definitions:

Definition of 'acidify'

(from WordNet)
verb
Make sour or more sour [syn: sour, acidify, acidulate, acetify] [ant: dulcify, dulcorate, edulcorate, sweeten]
verb
Turn acidic; "the solution acetified" [syn: acidify, acetify] [ant: alkalify, alkalise, alkalize, basify]

Synonyms of 'acidify'

From: Moby Thesaurus