資料來源 : Webster's Revised Unabridged Dictionary (1913)

Formyl \For"myl\, n. [Formic + -yl.] (Chem.)
   (a) A univalent radical, {H.C:O}, regarded as the essential
       residue of formic acid and aldehyde.
   (b) Formerly, the radical methyl, {CH3}.