Originally, a shield-bearer or armor-bearer, an attendant on a knight; in modern times, a title of dignity next in degree below knight and above gentleman; also, a title of office and courtesy; often shortened to squire.
in England, the title of esquire belongs by right of birth to the eldest sons of knights and their eldest sons in perpetual succession; to the eldest sons of younger sons of peers and their eldest sons in perpetual succession. It is also given to sheriffs, to justices of the peace while in commission, to those who bear special office in the royal household, to counselors at law, bachelors of divinity, law, or physic, and to others. In the united states the title is commonly given in courtesy to lawyers and justices of the peace, and is often used in the superscription of letters instead of Mr.
Origin: OF. Escuyer, escuier, properly, a shield-bearer, f. Ecuyer shield-bearer, armor-bearer, squire of a knight, esquire, equerry, rider, horseman, LL. Scutarius shield-bearer, fr. L. Scutum shield, akin to gr. Skin, hide, from a root meaning to cover; prob. Akin to E. Hide to cover. See hide to cover, and cf. Equerry, escutcheon.