Source : Webster's Revised Unabridged Dictionary (1913)

Multiplane \Mul"ti*plane\, a.
   Having several or many planes or plane surfaces; as, a
   multiplane kite.

Multiplane \Mul"ti*plane\, n. [Multi- + plane.] (A["e]ronautics)
   An a["e]roplane with three or more superposed main planes.