dutyyoudaoicibaDictYouDict[duty 词源字典]
duty: [13] Duty comes from Anglo-Norman dueté. This was a derivative of Old French deu ‘owed’ (source of English due [13]), which in turn came from Latin dēbitus, past participle of dēbēre ‘owe’ and source of English debit and debt. (Latin dēbēre was originally a compound verb formed from the prefix dē- ‘away’ and habēre ‘have’, literally ‘have away’, that is ‘keep in one’s possession what belongs to someone else’.) So etymologically one’s duty is what one ‘owes’ to others.
=> debit, debt, due[duty etymology, duty origin, 英语词源]
duty (n.)youdaoicibaDictYouDict
late 13c., from Anglo-French duete, from Old French deu "due, owed; proper, just," from Vulgar Latin *debutus, from Latin debitus, past participle of debere "to owe" (see debt). Related: Duties. The sense of "tax or fee on imports, exports, etc." is from late 15c.; duty-free as a noun is attested from 1958.