cardioid
noun Date: 1753 a heart-shaped curve that is traced by a point on the circumference of a circle rolling completely around an equal fixed circle and has an equation in one of the forms ρ = a(1 ± cos θ) or ρ = a(1 ± sin θ) in polar coordinates

New Collegiate Dictionary. 2001.

### Look at other dictionaries:

• Cardioid — is closed curve with one cusp.DefinitionIn geometry, the cardioid is an epicycloid with one cusp. Construction* epicycloid produced as the path (or locus) of a point on the circumference of a circle as that circle rolls around another fixed… …   Wikipedia

• Cardioid — Car di*oid, n. [Gr. kardio eidh s heart shaped; kardi a heart + e i^dos shape.] (Math.) An algebraic curve, so called from its resemblance to a heart. [1913 Webster] …   The Collaborative International Dictionary of English

• cardioid — [kär′dē oid΄] n. [Gr kardioeidēs, heart shaped < kardia, HEART + oeidēs, OID] Math. a curve more or less in the shape of a heart, traced by a point on the circumference of a circle that rolls around the circumference of another equal circle …   English World dictionary

• cardioid — noun 1》 Mathematics a heart shaped curve traced by a point on the circumference of a circle as it rolls around another identical circle. 2》 a directional microphone with a pattern of sensitivity of this shape. adjective of the shape of a cardioid …   English new terms dictionary

• cardioid — heart shaped …   Dictionary of ichthyology

• cardioid — /kahr dee oyd /, n. Math. a somewhat heart shaped curve, being the path of a point on a circle that rolls externally, without slipping, on another equal circle. Equation: r = a (1 cosA). [1745 55; < Gk kardioeidés heart shaped. See CARDI , OID] * …   Universalium

• cardioid — 1. noun An epicycloid with exactly one cusp; the plane curve with polar equation having a shape supposedly heart shaped 2. adjective Having this characteristic shape …   Wiktionary

• cardioid — Resembling a heart. [cardi + G. eidos, resemblance] * * * car·di·oid (kahrґde oid) heartlike; resembling a heart …   Medical dictionary

• cardioid — heart shaped Shapes and Resemblance …   Phrontistery dictionary

• cardioid — n. heart shaped geometrical figure (Mathematics) …   English contemporary dictionary