Carboxyl
Pronunciation : Car*box"yl
Part of Speech : n.
Etymology : [Carbon + oxygen + -yl.] (Chem.)
Definition : Defn: 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