elope (v.) Look up elope at Dictionary.com
1590s, "to run off," probably from Middle Dutch (ont)lopen "run away," from ont- "away from" (from Proto-Germanic *und- which also gave the first element in until) + lopen "to run," from Proto-Germanic *hlaupan (see leap (v.)). Sense of "run from parents to marry secretly" is 19c.

However there is an Anglo-French aloper "run away from a husband with one's lover" (mid-14c.) which complicates this etymology; perhaps it is a modification of the Middle Dutch word, with Old French es-, or it is a compound of that and Middle English lepen "run, leap" (see leap (v.)).

The oldest Germanic word for "wedding" is represented by Old English brydlop (cognates: Old High German bruthlauft, Old Norse bruðhlaup), literally "bride run," the conducting of the woman to her new home. Related: Eloped; eloping.