The Collaborative International Dictionary of English v.0.48:
down-bow \down-bow\ n. (Music) a downward stroke from the heel to the tip of the bow, in bowing a stringed instrument. Contrasted with up-bow, when the bow is moved in the opposite direction. [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
down-bow n 1: a downward stroke from the heel to the tip of the bow