The Collaborative International Dictionary
Metachloral
Metachloral \Met`a*chlo"ral\, n. [Pref. meta- + chloral.] (Chem.) A white, amorphous, insoluble substance regarded as a polymeric variety of chloral.
Wiktionary
metachloral
n. (context chemistry English) A white, amorphous, insoluble substance regarded as a polymeric variety of chloral.