Te*tarto*he"dral*ly

from The Collaborative International Dictionary of English v.0.48

Tetartohedral \Te*tar`to*he"dral\, a. [Gr. ? fourth + ? base.]
   (Crystallog.)
   Having one fourth the number of planes which are requisite to
   complete symmetry. -- {Te*tar`to*he"dral*ly}, adv.
   [1913 Webster]