adjective. Slightly sour in taste or in manner.

Slightly sour; subacid, as cream of tartar, oranges, gooseberries, etc.

Figuratively, sour in feeling or expression; sharp; caustic; harsh.

adjective. Slightly sour; sub-acid; sourish.

adjective. such as contain carbonic anhydride.

adjective. Slightly sour; sub-acid; sourish; as an acidulous tincture - Edmund Burke

adjective. being sour to the taste

"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."

sour  

aboleth  ammoniacal  anti-federalist  apple-tart  balsamic  

acerb  acerbate  acerbic  acetic  acetose