(n) a concave reflector used to produce a parallel beam when the source is placed at its focus or to focus an incoming parallel beam, Syn.paraboloid reflector
The Collaborative International Dictionary of English (GCIDE) v.0.53
{ } a. [ Gr. paraboliko`s figurative: cf. F. parabolique. See Parable. ] [ 1913 Webster ]
1. Of the nature of a parable; expressed by a parable or figure; allegorical; as, parabolical instruction. [ 1913 Webster ]
2. [ From Parabola. ] (Geom.) (a) Having the form or nature of a parabola; pertaining to, or resembling, a parabola; as, a parabolic curve. (b) Having a form like that generated by the revolution of a parabola, or by a line that moves on a parabola as a directing curve; as, a parabolic conoid; a parabolic reflector; a parabolic antenna. [ 1913 Webster +PJC ]
Parabolic conoid, a paraboloid; a conoid whose directing curve is a parabola. See Conoid. -- Parabolic mirror (Opt.), a mirror having a paraboloidal surface which gives for parallel rays (as those from very distant objects) images free from aberration. It is used in reflecting telescopes. -- Parabolic spindle, the solid generated by revolving the portion of a parabola cut off by a line drawn at right angles to the axis of the curve, about that line as an axis. -- Parabolic spiral, a spiral curve conceived to be formed by the periphery of a semiparabola when its axis is wrapped about a circle; also, any other spiral curve having an analogy to the parabola. [ 1913 Webster ]
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