French Words with e for o in Unaccented Initial Syllables

[In OFr. words of the type mencie < moneta, peroindre < poroindre the e is a weakening of the o when adjacent to a liquid or nasal which tended to be syllabic. This phenomenon was more frequent in eastern dialects. The progressive changes of an o in this position, to judge from modern dialect forms, must have been poroindre > peroindre or paroindre > proindre. The last form, with zero grade of the vowel, was seldom written in the older texts because of conservatism in spelling.]