The Collaborative International Dictionary
Metacrolein
Metacrolein \Met`a*cro"le*in\, n. [Pref. met- + acrolein.] (Chem.) A polymeric modification of acrolein obtained by heating it with caustic potash. It is a crystalline substance having an aromatic odor.
Wiktionary
metacrolein
n. (context chemistry English) A polymeric modification of acrolein obtained by heating it with caustic potash.