Source : Webster's Revised Unabridged Dictionary (1913)

Elopement \E*lope"ment\, n.
   The act of eloping; secret departure; -- said of a woman and
   a man, one or both, who run away from their homes for
   marriage or for cohabitation.

Source : WordNet®

elopement
     n : the act of running away with a lover (usually to get
         married)