Source : Webster's Revised Unabridged Dictionary (1913)

Pinon \Pi[~n]"on\, n. [Sp. pi[~n]on.] (Bot.)
      (a) The edible seed of several species of pine; also, the
          tree producing such seeds, as {Pinus Pinea} of
          Southern Europe, and {P. Parryana, cembroides, edulis,
          and monophylla}, the nut pines of Western North
          America.
      (b) See {Monkey's puzzle}. [Written also {pignon}.]