The Collaborative International Dictionary of English v.0.48:

Osculation \Os`cu*la"tion\, n. [L. osculatio a kissing: cf. F.
   osculation.]
   1. The act of kissing; a kiss.
      [1913 Webster]

   2. (Geom.) The contact of one curve with another, when the
      number of consecutive points of the latter through which
      the former passes suffices for the complete determination
      of the former curve. --Brande & C.
      [1913 Webster]

WordNet (r) 3.0 (2006):

osculation
    n 1: (mathematics) a contact of two curves (or two surfaces) at
         which they have a common tangent
    2: the act of caressing with the lips (or an instance thereof)
       [syn: kiss, buss, osculation]