banyoudaoicibaDictYouDict[ban 词源字典]
ban: [OE] Ban is one of a widespread group of words in the European languages. Its ultimate source is the Indo-European base *bha-, which also gave English fame (from a derivative of Latin fārī ‘speak’) and phase (from Greek phāsis). The Germanic offshoot of the Indo- European base, and source of the English word, was *bannan, which originally probably meant simply ‘speak, proclaim’.

This gradually developed through ‘proclaim with threats’ to ‘put a curse on’, but the sense ‘prohibit’ does not seem to have arisen until as late as the 19th century. The Germanic base *bann- was borrowed into Old French as the noun ban ‘proclamation’. From there it crossed into English and probably mingled with the cognate English noun, Middle English iban (the descendant of Old English gebann).

It survives today in the plural form banns ‘proclamation of marriage’. The adjective derived from Old French ban was banal, acquired by English in the 18th century. It originally meant ‘of compulsory military service’ (from the word’s basic sense of ‘summoning by proclamation’); this was gradually generalized through ‘open to everyone’ to ‘commonplace’.
=> banal, bandit, banish, contraband, fame, phase[ban etymology, ban origin, 英语词源]
ban (v.)youdaoicibaDictYouDict
Old English bannan "to summon, command, proclaim," from Proto-Germanic *bannan "proclaim, command, forbid" (cognates: Old High German bannan "to command or forbid under threat of punishment," German bannen "banish, expel, curse"), originally "to speak publicly," from PIE root *bha- (2) "to speak" (cognates: Old Irish bann "law," Armenian ban "word;" see fame (n.)).

Main modern sense of "to prohibit" (late 14c.) is from Old Norse cognate banna "to curse, prohibit," and probably in part from Old French ban, which meant "outlawry, banishment," among other things (see banal) and was a borrowing from Germanic. The sense evolution in Germanic was from "speak" to "proclaim a threat" to (in Norse, German, etc.) "curse."

The Germanic root, borrowed in Latin and French, has been productive: banish, bandit, contraband, etc. Related: Banned; banning. Banned in Boston dates from 1920s, in allusion to the excessive zeal and power of that city's Watch and Ward Society.
ban (n.2)youdaoicibaDictYouDict
"governor of Croatia," from Serbo-Croatian ban "lord, master, ruler," from Persian ban "prince, lord, chief, governor," related to Sanskrit pati "guards, protects." Hence banat "district governed by a ban," with Latinate suffix -atus. The Persian word got into Slavic perhaps via the Avars.
ban (n.1)youdaoicibaDictYouDict
"edict of prohibition," c. 1300, "proclamation or edict of an overlord," from Old English (ge)bann "proclamation, summons, command" and Old French ban, both from Germanic; see ban (v.).