D defs.my
Entry 1 sense Webster, 1913

Cissoid

· Cis·soid · IPA
01 n. A curve invented by Diocles, for the purpose of solving two celebrated problems of the higher geometry; viz., to trisect a plane angle, and…
  1. 1.
    A curve invented by Diocles, for the purpose of solving two celebrated problems of the higher geometry; viz., to trisect a plane angle, and to construct two geometrical means between two given straight lines.(Geom.)