Source : Webster's Revised Unabridged Dictionary (1913)

Acrolein \A*cro"le*in\, n. [L. acer sharp + ol[=e]re to smell.]
   (Chem.)
   A limpid, colorless, highly volatile liquid, obtained by the
   dehydration of glycerin, or the destructive distillation of
   neutral fats containing glycerin. Its vapors are intensely
   irritating. --Watts.

Source : WordNet®

acrolein
     n : a pungent colorless unsaturated liquid aldehyde made from
         propene [syn: {propenal}]