Source : Webster's Revised Unabridged Dictionary (1913)

Pennon \Pen"non\, n. [Cf. {Pinion}.]
   A wing; a pinion. --Milton.

Pennon \Pen"non\, n. [See {Pennant}.]
   A pennant; a flag or streamer. --Longfellow.

Source : WordNet®

pennon
     n 1: a long flag; often tapering [syn: {pennant}, {streamer}, {waft}]
     2: wing of a bird [syn: {pinion}]