The Collaborative International Dictionary
Plagihedral
Plagihedral \Pla`gi*he"dral\, a. [Gr. pla`gios oblique + ? base, seat.] (Crystallog.) Having an oblique spiral arrangement of planes, as levogyrate and dextrogyrate crystals.
Wiktionary
plagihedral
a. (context crystallography English) Having an oblique spiral arrangement of planes, as in levogyrate and dextrogyrate crystals.