What is (a) A hydrocarbon radical (C2O2) regarded as a residue of oxalic acid and occurring in derivatives of it. (b) An old name for carbonyl. (c) An old name for carboxyl called?

oxalyl — (a) A hydrocarbon radical (C2O2) regarded as a residue of oxalic acid and occurring in derivatives of it. (b) An old name for carbonyl. (c) An old name for carboxyl. (Webster's 1913.)

Sources