Source : Webster's Revised Unabridged Dictionary (1913)

Amour \A*mour"\, n. [F., fr. L. amor love.]
   1. Love; affection. [Obs.]

   2. Love making; a love affair; usually, an unlawful
      connection in love; a love intrigue; an illicit love
      affair.

   {In amours with}, in love with. [Obs.]

Source : WordNet®

amour
     n : a usually secretive or illicit sexual relationship [syn: {affair},
          {affaire}, {intimacy}, {liaison}, {involvement}]