Chapter Caracara to Carboxyl of C by Webster's Dictionary (1913 Edition)

Carboxide
(Car*box"ide) n. [Carbon + oxide.] (Chem.) A compound of carbon and oxygen, as carbonyl, with some element or radical; as, potassium carboxide.

Potassium carboxide, a grayish explosive crystalline compound, C₆O₆K, obtained by passing carbon monoxide over heated potassium.

Carboxyl
(Car*box"yl) n. [Carbon + oxygen + -yl.] (Chem.) 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.