D defs.my
Entry 1 sense Webster, 1913

Carboxyl

/(kär*bŏks"ĭl)/ · Car·box·yl · IPA /kɑː(ɹ)ˈbɒksɪl/
01 n. The complex radical, CO.OH, regarded as the essential and characteristic constituent which all oxygen acids of carbon (as formic, acetic, b…
  1. 1.
    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.(Chem.) Also: oxatyl