cissoid
noun
cis·soid
ˈsiˌsȯid
plural -s
: a plane curve with two branches meeting at a cusp at one end of a diameter of a fixed circle, each point of the cissoid being obtained by going from the cusp along any chord to its intersection when extended with the tangent diametrically opposite the cusp and then returning along the extended chord a distance equal to the length of the chord
cissoidal adjective
(ˈ)si¦sȯidᵊl
Word History
Etymology
Late Greek kissoeidēs, from Greek, like ivy, from kissos ivy + -oeidēs -oid