Prefix of verbs and action nouns adopted from OF, e.g. es-cāpen, es-chaunǧen, es-pleiten, es-soinen. It is not formative in ME. as- and a-, the AF variants of this prefix, occur alongside the CF form in such words as as-cāpen, a(s)-soinen, a(s)-maien. ex-, the Latin source of OF es-, frequently appears as a variant in such words as es-chaungen, es-cūsen [L ex-cūsāre], es-pleit, ess-aumple [L ex-emplum].