The Collaborative International Dictionary of English v.0.48:

Flirtation \Flir*ta"tion\, n.
   1. Playing at courtship; coquetry.
      [1913 Webster]

            The flirtations and jealousies of our ball rooms.
                                                  --Macaulay.
      [1913 Webster]

WordNet (r) 3.0 (2006):

flirtation
    n 1: playful behavior intended to arouse sexual interest [syn:
         flirt, flirting, flirtation, coquetry, dalliance,
         toying]