-yl Look up -yl at Dictionary.com
chemical suffix used in forming names of radicals, from French -yle, from Greek hyle "wood," also "building stuff, raw material" (from which something is made), 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]