The Collaborative International Dictionary
Methenyl
Methenyl \Meth"e*nyl\, n. [Methene + -yl.] (Chem.) The hypothetical hydrocarbon radical CH, regarded as an essential residue of certain organic compounds.
Wiktionary
methenyl
n. (context chemistry English) The hypothetical hydrocarbon radical CH, regarded as an essential residue of certain organic compounds.