v. to make something (more) acidic or sour; to convert into an acid.
v. to neutralize alkalis, as to acidify sugar
v. to sour, to embitter.
the GNU version of the Collaborative International Dictionary of English
v. To make acid; to convert into an acid.
v. To sour; to imbitter.
The Century Dictionary and Cyclopedia
To make acid; convert into an acid; render sour; sour, literally or figuratively.
To become acid or sour.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
v. turn acidic
v. make sour or more sour
Word Usage
"Because excess CO2 dissolves in the ocean - causing it to 'acidify' - researchers have been concerned about the ability of certain organisms to maintain the strength of their shells."