noun hep·ta·phyllite \¦heptə+\

Definition of heptaphyllite

  1. :  any of a group of micas (as muscovite and other light-colored micas) with seven metallic ions per ten oxygen and two hydroxyl ions — compare octaphyllite

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Origin and Etymology of heptaphyllite

hepta- + phyllite

Seen and Heard

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to criticize severely

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