Source : Webster's Revised Unabridged Dictionary (1913)

Knight banneret \Knight" ban"ner*et\; pl. {Knights bannerets}.
   A knight who carried a banner, who possessed fiefs to a
   greater amount than the knight bachelor, and who was obliged
   to serve in war with a greater number of attendants. The
   dignity was sometimes conferred by the sovereign in person on
   the field of battle.