parabolic mirror

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A concave mirror, generally circular and with a parabolic cross-section, used either to concentrate radiation reflected from its surface onto a central focal point (as in a parabolic antenna) or to direct radiation emitted by the central focal point and reflected from the mirror into parallel beams (as in an automobile's headlights).

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a parabolic reflector for light radiation