elopement (n.)

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, from PIE root *ant- "front, forehead," with derivatives meaning "in front of, before") + lopen "to run," from Proto-Germanic *hlaupan (source also of Old English hleapan; see leap (v.)). Sense of "run away in defiance of parental authority to marry secretly" is 19c.

In support of this OED compares Old English uðleapan, "the technical word for the 'escaping' of a thief." 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 (source also of Old High German bruthlauft, Old Norse bruðhlaup), literally "bride run," the conducting of the woman to her new home. Related: Eloped; eloping.

common suffix of Latin origin forming nouns, originally from French and representing Latin -mentum, which was added to verb stems to make nouns indicating the result or product of the action of the verb or the means or instrument of the action. In Vulgar Latin and Old French it came to be used as a formative in nouns of action. French inserts an -e- between the verbal root and the suffix (as in commenc-e-ment from commenc-er; with verbs in ir, -i- is inserted instead (as in sent-i-ment from sentir).

Used with English verb stems from 16c. (for example amazement, betterment, merriment, the last of which also illustrates the habit of turning -y to -i- before this suffix).

The stems to which -ment is normally appended are those of verbs; freaks like oddment & funniment should not be made a precedent of; they are themselves due to misconception of merriment, which is not from the adjective, but from an obsolete verb merry to rejoice. [Fowler]