cissoid

American  

[sis-oid] / ˈsɪs ɔɪd /

noun

Geometry.

1. a curve having a cusp at the origin and a point of inflection at infinity. Equation: r = 2 a sin(θ)tan(θ).

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cissoid British  

/ ˈsɪsɔɪd /

noun

1. a geometric curve whose two branches meet in a cusp at the origin and are asymptotic to a line parallel to the y -axis. Its equation is y ²(2a – x ) =x ³ where 2a is the distance between the y -axis and this line

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adjective

1. contained between the concave sides of two intersecting curves Compare sistroid

Other Word Forms

• cissoidal adjective

Etymology

Origin of cissoid

1650–60; < Greek kissoeidḗs, equivalent to kiss ( ós ) ivy + -oeidēs -oid