macropinacoid

1 definition found

macropinacoid - Collaborative International Dictionary of English v.0.48 :

  Macropinacoid \Mac`ro*pin"a*coid\, n. [Macro- + pinacoid.]
     (Crystallog.)
     One of the two planes of an orthorhombic crystal which are
     parallel to the vertical and longer lateral (macrodiagonal)
     axes.
     [1913 Webster]