the form of a before an initial vowel sound (an arch; an honor) and sometimes, especially in British English, before an initial unstressed syllable beginning with a silent or weakly pronounced h:
a suffix occurring originally in adjectives borrowed from Latin, formed from nouns denoting places (Roman; urban) or persons (Augustan), and now productively forming English adjectives by extension of the Latin pattern. Attached to geographic names, it denotes provenance or membership (American; Chicagoan; Tibetan), the latter sense now extended to membership in social classes, religious denominations, etc., in adjectives formed from various kinds of noun bases (Episcopalian; pedestrian; Puritan; Republican) and membership in zoological taxa (acanthocephalan; crustacean). Attached to personal names, it has the additional senses “contemporary with” (Elizabethan; Jacobean) or “proponent of” (Hegelian; Freudian) the person specified by the noun base. The suffix -an, and its variant -ian also occurs in a set of personal nouns, mainly loanwords from French, denoting one who engages in, practices, or works with the referent of the base noun (comedian; grammarian; historian; theologian); this usage is especially productive with nouns ending in -ic (electrician; logician; technician). See -ian for relative distribution with that suffix.
Origin of -an
Middle English < Latin -ānus, -āna, -ānum; in some words replacing -ain, -en < Old French < Latin suffix (forming adjectives and nouns) belonging to or relating to; a person belonging to or coming fromEuropean (forming adjectives and nouns) typical of or resembling; a person typical ofElizabethan (forming adjectives and nouns) adhering to or following; an adherent ofChristian (forming nouns) a person who specializes or is expert indietitian; phonetician Word Origin and History for an indefinite article before words beginning with vowels, 12c., from Old English an (with a long vowel) “one; lone,” also used as a prefix an- “single, lone;” see one for the divergence of that word from this. Also see a, of which this is theolder, fuller form. In other European languages, identity between indefinite article and the word for “one” remains explicit (e.g. French un, German ein, etc.) Old English got by without indefinite articles: He was a good man in Old English was he wæs god man. Circa 15c., a and an commonly were written as one word with the following noun, which contributed to the confusion over how such words as newt and umpire ought to be divided (see N). In Shakespeare, etc., an sometimes is a contraction of as if (a usage first attested c.1300), especially before it.