osculation osculation /ˌɒskjʊˈleɪʃən/

noun

1. The act of caressing with the lips (or an instance thereof)  ( buss [Informal, N. American] , osculation , kiss )
   the act of caressing with the lips (or an instance thereof)
     They shared a passionate kiss under the starry night sky.
   They shared a passionate kiss under the starry night sky.
   
   
2. (mathematics) a contact of two curves (or two surfaces) at which they have a common tangent  ( osculation )
   (mathematics) a contact of two curves (or two surfaces) at which they have a common tangent