hemi·he·dral \| ̷ ̷ ̷ ̷+|hēdrəl\adjective orhemi·he·dric\-rik\ Etymology:hemi- (I) + -hedron + -al or -ic 1.of a crystal: having half the faces required by complete symmetry — compare holohedral 2.: having the symmetry appropriate to a hemihedral form • hemi·he·dral·ly\-rəlē\adverb