The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]