D defs.my
Entry 1 sense Webster, 1913

Orthopinacoid

· Or·tho·pin·a·coid · IPA
01 n. A name given to the two planes in the monoclinic system which are parallel to the vertical and orthodiagonal axes.
  1. 1.
    A name given to the two planes in the monoclinic system which are parallel to the vertical and orthodiagonal axes.(Crystallog.)