Origin and history of fentanyl

before vowels phen-, word-forming element in science meaning "pertaining to or derived from benzene;" see -phene.

chemical suffix used in forming names of radicals, from French -yle, from Greek hylē "wood," also "building stuff, raw material" (from which something is made), a word of unknown origin. The use in chemistry traces to the latter sense (except in methylene, where it means "wood").

It was introduced into chemical nomenclature by Liebig and Wohler when, in 1832, they used the term benzoyle for the radical which appeared to be the "essential material" of benzoic acid and related compounds. [Flood]