CARBOXYL
carboxyl, carboxylic
(adjective) relating to or containing the carboxyl group or carboxyl radical
carboxyl, carboxyl group
(noun) the univalent radical -COOH; present in and characteristic of organic acids
Source: WordNet® 3.1
Noun
carboxyl (plural carboxyls)
(organic chemistry) A univalent functional group consisting of a carbonyl and a hydroxyl functional group (-CO.OH); characteristic of carboxylic acids.
Source: Wiktionary
Car*box"yl, n. Etym: [Carbon + oxygen + -yl.] (Chem.)
Definition: 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.
Source: Webster’s Unabridged Dictionary 1913 Edition