-ansuffix

a. repr. Latin -ānus, -āna, -ānum ‘of, or belonging to’; as castellān-us, oppidān-us, pāgān-us, urbān-us, silvān-us, Africān-us, Rōmān-us, Sullān-us, Justiniān-us. In Old French this became -ain, or (after i) -en, as chastelain, Romain, payen, Italien; and so originally adopted in Middle English, but subseq. refashioned after Latin as -an, and so in all words formed in English direct, or adopted from the mod. langs. (Italian Spanish Portuguese -ano, French -ain, -en.). Esp. added to proper names; ‘belonging to a place’ as American, Chilean, Russian, Oxonian; ‘following a founder,’ as Arminian, Lutheran, Muhammadan, Linnæan, or ‘a system,’ as Episcopalian, Presbyterian, Anglican, Gallican; and, in Zoology, to names of divisions, ‘belonging to a class or order,’ as mammalian, reptilian, crustacean, arachnidan, acalephan. Primarily these are all adjs., but as in Latin etc., all may be used subst., and with some this is the more frequent use. The zoological words supply singulars to the collective plurals in -a, as a crustacean = a member of the Crustacea. Already in Latin this termination was often added to others, to -i-us so commonly that -iānus, -ian suffix, is in use merely a euphonic variety of -an; cf. Corinth-i-an, Rom-an, Christ-i-an, Muhammad-an.

b. in Chem. for -ane, arbitrary ending proposed by Davy for names of chlorides containing one atom of chlorine, as in azotan obs. In some words -an is a meaningless formative as allox-an.

a. In Old English, ending of oblique cases, and nom. pl. of weak declension. Both became in Middle English -en, now rarely preserved in pl., as ox-en:—Old English ox-an. Hence (dat. or loc. sing.) in advb. or prep. forms like ut-an, abut-an, befor-an, Middle English uten, abuten, and ute, abute. Now obs.

b. In Old English, ending of pres. inf. of vbs., levelled in Middle English to -en, -e, and now lost, as Old English writ-an, send-an; Middle English writ-e(n, send-e(n; mod. write, send.