es-, prefix
occurring in adoptions of OF. words beginning with es-:—L. ex- out. A few of these words survive with the prefix unchanged, as escape, escheat; a few others have been refashioned with ex-, after Latin, as esample, now example, eschange, now exhange; but the much larger number of them are obsolete. Before ch this prefix was in 14–15th c. occasionally written eþ-. A frequent variant of es- is a-: see a- prefix 9.
¶ The examples of the prefix es- must be distinguished from those of the euphonic e prefixed in OF. (as in Pr., Sp., Pg.) to an initial s followed by a consonant, e.g. especial, esquire.