The Collaborative International Dictionary
Ethenyl
Ethenyl \Eth"e*nyl\, n. [Ethene + -yl.] (Chem.)
A trivalent hydrocarbon radical, CH3.C.
A univalent hydrocarbon radical of the ethylene series, CH2:CH; -- called also vinyl. See Vinyl.
Wiktionary
ethenyl
n. (context chemistry English) vinyl