adj. Slightly sour; sub-acid; sourish; as an acidulous tincture - Edmund Burke
the GNU version of the Collaborative International Dictionary of English
adj. Slightly sour; sub-acid; sourish.
The Century Dictionary and Cyclopedia
Slightly sour; subacid, as cream of tartar, oranges, gooseberries, etc.
Figuratively, sour in feeling or expression; sharp; caustic; harsh.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. being sour to the taste
Word Usage
"He wanted to cancel the project — unless I was willing to expand my introduction, incorporating some of the acidulous commentary into a calmer treatment of the matter."