The Collaborative International Dictionary of English v.0.48:
Deflector \De*flect"or\, n. (Mech.) That which deflects, as a diaphragm in a furnace, or a cone in a lamp (to deflect and mingle air and gases and help combustion). [1913 Webster]WordNet (r) 3.0 (2006):
deflector n 1: a device intended to turn aside the flow of something (water or air or smoke etc)