osculate

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To kiss.
2. v. Mathematics To have three or more points coincident with.
3. v. To come together; contact.

Century Dictionary and Cyclopedia

1. To salute with a kiss; kiss.
2. In geometry, to have a higher contact with; touch as closely as possible. Thus, a plane or a circle is said to osculate a curve when it has three coincident points in common with the curve — that is, it occupies such a position (and in the case of the circle has such a size) that as it is brought up into this position three points of intersection with the curve run into one. A sphere is said to osculate a tortuous curve when it has four coincident points in common with the curve. In these cases, to osculate means to have the greatest number of coincident and successive points common to a fixed locus which is compatible with the general character of the locus which osculates; and some geometers restrict the word to this meaning. This meaning is also extended to time: thus, the osculating elements of a planet are those elliptic elements which would satisfy three exact observations made at times infinitely little removed from a given epoch. But osculate is also used loosely to mean merely that the loci in question have three or more coincident points in common. A tangent-line or-plane is never said to osculate a curve or surface unless it has more than ordinary contact with it.
3. To kiss one another; kiss.
4. In geometry, to have, as two loci, three or more coincident and successive points in common. See I., 2.
5. In natural history, to share the characters of another group.

Wiktionary

1. v. transitive To kiss someone or something.
2. v. mathematics To touch so as to have a common tangent at the point of contact.
3. v. intransitive To make contact.
4. v. To perform osculation.

GNU Webster's 1913

1. v. To kiss.
2. v. (Geom.) To touch closely, so as to have a common curvature at the point of contact. See Osculation, 2.
3. v. To kiss one another; to kiss.
4. v. (Geom.) To touch closely. See Osculation, 2.
5. v. (Biol.) To have characters in common with two genera or families, so as to form a connecting link between them; to interosculate. See Osculant.

WordNet 3.0

1. v. have at least three points in common with
2. v. touch with the lips or press the lips (against someone's mouth or other body part) as an expression of love, greeting, etc.
3. v. be intermediate between two taxonomic groups