vinylidene group

or vi·nyl·i·dene rad·i·cal

[ vahy-nil-i-deen groop or vahy-nil-i-deen rad-i-kuh l ]
/ vaɪˈnɪl ɪˌdin ˌgrup or vaɪˈnɪl ɪˌdin ˌræd ɪ kəl /

noun Chemistry.

the bivalent group C2H2, derived from ethylene.

Origin of vinylidene group