Orthopinacoid

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Orthopinacoid \Or`tho*pin"a*coid\, n. [Ortho- + pinacoid.]
     (Crystallog.)
     A name given to the two planes in the monoclinic system which
     are parallel to the vertical and orthodiagonal axes.
     [1913 Webster] Orthopnoea