'Cardioid' definitions:
Definition of 'cardioid'
From: WordNet
noun
An epicycloid in which the rolling circle equals the fixed circle
Definition of 'Cardioid'
From: GCIDE
- 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]