IPA: /ˈbɪtərɪŋ/
KK: /ˈbɪtərɪŋ/
A substance that has a sharp, unpleasant taste, often used in making beer or other beverages.
The brewer added a bittering agent to enhance the flavor of the beer.
Bittering → It is formed from "bitter" (from Old English "biter", meaning having a sharp taste) and "-ing" (a suffix used to form nouns indicating an action or process). The word "bittering" refers to the process of becoming bitter or the state of being bitter.
Think of the sharp taste of something 'bitter' — the '-ing' indicates the process, so 'bittering' means the process of becoming bitter.