di-ˈallylChem. [di-2.] A.n. The organic radical allyl in the free state, C6 H10= C3H5·C3H5: see allyl. B.attrib. and Comb. Containing two equivalents of allyl. 1869Roscoe Elem.Chem. 389. 1880 E. Cleminshaw tr.Wurtz' Atomic Th. 265 Free allyl or daillyl, has doubled its molecule.