osculation vs deep kiss

osculation and deep kiss both are nouns.

Word	Noun	Adjective	Verb	Adverb
osculation	Yes	No	No	No
deep kiss	Yes	No	No	No

As nouns, deep kiss is a hyponym of osculation; that is, deep kiss is a word with a more specific, narrower meaning than osculation:

osculation: the act of caressing with the lips (or an instance thereof)
deep kiss: an openmouthed kiss in which your tongue is inserted into the other's mouth

Other hyponyms of osculation include smack, smooch, French kiss, soul kiss, peck.

osculation (noun)	deep kiss (noun)
the act of caressing with the lips (or an instance thereof)	an openmouthed kiss in which your tongue is inserted into the other's mouth
(mathematics) a contact of two curves (or two surfaces) at which they have a common tangent