D defs.my
Entry 1 sense Webster, 1913

Conchoid

/kän'-choid/ · Con·choid · IPA /kˈɑntʃɔɪd/
01 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 a…
  1. 1.
    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.(Geom.)