Conchoid

(n.) A curve, of the fourth degree, first made use of by the Greek geometer, Nicomedes, who invented it for the purpose of trisecting an angle and duplicating the cube.

Thesaurus Entries

AC arc, Poulsen arc, aperiodic discharge, arc column, arc discharge, arc light, arch, bend, bow, brush discharge, catacaustic, catenary, caustic, circle, color filter, conchoid, crook, curl, curvation, curvature, curve, diacaustic, dimmer, discharge, disruptive discharge, electric discharge, electric shock, electric spark, electrodeless discharge, ellipse, festoon, floats, flood, floodlight, footlights, foots, galvanic shock, gelatin, glow discharge, hook, hyperbola, klieg light, light plot, lights, limelight, lituus, marquee, medium, oscillatory discharge, parabola, round, shock, silent discharge, sinus, spark, spark gap, spot, spotlight, tracery