Etymology: < classical Latin as-, assimilated form of ad- ad- prefix before s- , as in assentīre assent v., assignāre assign v. The usual reflex in Old French was a- , which is sometimes reflected in Middle English borrowings, as in asent , acent , early variants of assent v. and assent n., or asigne , early variant of assign v. Under classicizing influence, the spelling as- was generally restored in Middle French, and likewise ultimately in English.The same respelling was apparently applied analogously to a number of words which do not in fact etymologically show Latin as- at all: compare e.g. asaumple n., assoil v., and discussion at those entries. Occasional new formations within English are found apparently from the 17th cent. (compare asself v. asservile v.).

Etymology: < Anglo-Norman as-, variant of Old French es- es- prefix < classical Latin ex- ex- prefix¹, as in ascape v., asaumple n., assart v., assay v., achue (see eschew v.¹), assoin n., astonish v. In some words this form is still retained; in others it has been altered back to es- (after Old French es- ), as in escape v., essay v., eschew v.¹, or to ex- (after Latin ex- ), as in example n.; in others the a- has been lost by aphesis, as in scape v.¹, sample n.