'Cissoid' definitions:
Definition of 'Cissoid'
From: GCIDE
- Cissoid \Cis"soid\, n. [Gr. ? like ivy; ? ivy + e'i^dos form.] (Geom.) 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. [1913 Webster]