deflector

noun

1. Something which deflects something else, especially a stream of fluid or particles.

   “1992 Nasa Patents Available for Licensing from the George C. Marshall Space Flight Center The deflector assembly contains a plurality of vanes which change the direction of the solar energy to the vertical, while constantly keeping the same side of the deflector facing the sun.”

2. A diaphragm in a lamp, stove, etc. by which the flame and gases are brought together to improve combustion.
3. A force field; an invisible barrier used as a protective shield.

   “The blasters are those beams of ravening destruction which take care of recalcitrant meteorites in a spaceship's course when the deflectors can't handle them.”

   “Deflectors say there's something there, sensors say there isn't. Density negative. Radiation negative. Energy negative.”

   “PICARD: If the Romulans have returned to this sector we should know about that. Mister Worf, any further activity? WORF: Negative, sir. PICARD: Slow to half impulse. LAFORGE: Going to one half impulse. ... Now entering quadrant nine-zero-seven, mark three. PICARD: Shields and deflectors up. Go to Yellow Alert.”