osculant

Etymology
From, , present participle of. See.

Adjective

 * 1) Kissing; hence, touching or meeting; clinging.
 * 2)  Adhering closely; applied to certain creeping animals, such as caterpillars.
 * 3)  Intermediate between two genera, groups, families, etc., and having some of the characteristics of each; interosculant.
 * The genera by which two families approximate are called osculant genera.
 * 1)  Intermediate between multiple potentially reconstructible protoforms, but having a mismatch in semantics or morphology that cannot be explained through regular patterns of change.
 * 2)  Tangent, touching at a single point.

Noun

 * 1)  The point at which two tangent curves touch.
 * 2)  The condition that the solution to a set of simultaneous quantics, is also the solution of the corresponding set of tangential quantics.

Noun

 * 1)  a form of tacinvariant of hypersurfaces that have a point in common