The Collaborative International Dictionary of English v.0.48:

Kiss \Kiss\ (k[i^]s), v. t. [imp. & p. p. Kissed (k[i^]st);p.
   pr. & vb. n. Kissing.] [OE. kissen, cussen, AS. cyssan, fr.
   coss a kiss; of uncertain origin; akin to D. kus, G. kuss,
   Icel. koss.]
   1. To salute with the lips, as a mark of affection,
      reverence, submission, forgiveness, etc.
      [1913 Webster]

            He . . . kissed her lips with such a clamorous
            smack,
            That at the parting all the church echoed. --Shak.
      [1913 Webster]

   2. To touch gently, as if fondly or caressingly.
      [1913 Webster]

            When the sweet wind did gently kiss the trees.
                                                  --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

kissing
    n 1: affectionate play (or foreplay without contact with the
         genital organs) [syn: caressing, cuddling, fondling,
         hugging, kissing, necking, petting, smooching,
         snuggling]