Osculate

In mathematics, osculate, meaning to touch (from the Latin osculum meaning kiss), may refer to:


 * osculant, an invariant of hypersurfaces
 * osculating circle
 * osculating curve
 * osculating plane
 * osculating orbit
 * osculating sphere

The obsolete Quinarian system of biological classification attempted to group creatures into circles which could touch or overlap with adjacent circles, a phenomenon called 'osculation'.