relating to or containing the carboxyl group or carboxyl radical
source: WordNet 3.0
noun
the univalent radical -COOH; present in and characteristic of organic acids
source: WordNet 3.0
The complex radical, CO.OH, regarded as the essential and characteristic constituent which all oxygen acids of carbon (as formic, acetic, benzoic acids, etc.) have in common; -- called also oxatyl.