Source : Webster's Revised Unabridged Dictionary (1913)

Propenyl \Pro"pe*nyl\, n. [Propene + -yl.] (Chem.)
   A hypothetical hydrocarbon radical, {C3H5}, isomeric with
   allyl and glyceryl, and regarded as the essential residue of
   glycerin. Cf. {Allyl}, and {Glyceryl}.