Source : Webster's Revised Unabridged Dictionary (1913)

Plancher \Planch"er\, n. [F., planche. See {Planch}.]
   1. A floor of wood; also, a plank. [Obs.] --Bacon.

   2. (Arch.) The under side of a cornice; a soffit.

Plancher \Planch"er\, v. t.
   To form of planks. [Obs.] --Golding.