osculate

[os-kyuh-leyt] /ˈɒs kyəˌleɪt/
verb (used without object), osculated, osculating.
1.
to come into close contact or union.
2.
Geometry. (of a curve) to touch another curve or another part of the same curve so as to have the same tangent and curvature at the point of contact.
verb (used with object), osculated, osculating.
3.
to bring into close contact or union.
4.
Geometry. (of a curve) to touch (another curve or another part of the same curve) in osculation.
5.
to kiss.
Origin
1650-60; < Latin ōsculātus (past participle of ōsculārī to kiss), equivalent to ōscul(um) kiss, literally, little mouth (see osculum) + -ātus -ate1
Related forms
osculatory
[os-kyuh-luh-tawr-ee, -tohr-ee] /ˈɒs kyə ləˌtɔr i, -ˌtoʊr i/ (Show IPA), adjective
unosculated, adjective
Can be confused
oscillate, osculate.
British Dictionary definitions for osculate

osculate

/ˈɒskjʊˌleɪt/
verb
1.
generally (jocular) to kiss
2.
(intransitive) (of an organism or group of organisms) to be intermediate between two taxonomic groups
3.
(geometry) to touch in osculation
Word Origin
C17: from Latin ōsculārī to kiss; see osculum
Word Origin and History for osculate
v.

"to kiss," 1650s, from Latin osculatus, past participle of osculari "to kiss," from osculum "a kiss; pretty mouth, sweet mouth," literally "little mouth," diminutive of os "mouth" (see oral). Related: Osculated; osculating.