Osculation

Part of speech: noun

Pronunciation: /ˌɒs.kjʊˈleɪ.ʃən/

Definitions

1. The action of pressing lips together as a sign of affection or greeting ; the exact point or line where two curves or surfaces touch without intersecting
2. A gentle or romantic lip-to-lip contact between people ; a contact point where one geometric shape just touches another without crossing
3. An intimate or friendly kiss shared between individuals ; a tangent point indicating where smooth curves or surfaces meet delicately

Etymology: Latin "osculum" meant "little mouth" and was a diminutive of "os," the ordinary word for mouth, so a kiss was literally a small-mouth contact. From it came "ōsculārī," "to kiss," and the noun "ōsculātiō," "a kissing," which is the direct source of English "osculation." The English word therefore keeps a Latin sense of kissing that has nothing to do with geometry. The mathematical sense is the surprise. The word was borrowed into English with its plain meaning of kissing, and the geometric use of touching curves or surfaces without crossing came later, as mathematicians borrowed the same vocabulary to describe contact between curves. A pair of curves that osculate share a point and move together there, like two people leaning in to meet.

Synonyms: kiss, peck