The Collaborative International Dictionary of English v.0.48:

Snuggle \Snug"gle\, v. t. [imp. & p. p. Snuggled; p. pr. & vb.
   n. Snuggling.] [Freq. of snug.]
   To move one way and the other so as to get a close place; to
   lie close for comfort; to cuddle; to nestle.
   [1913 Webster]

WordNet (r) 3.0 (2006):

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