answeryoudaoicibaDictYouDict[answer 词源字典]
answer: [OE] Etymologically, the word answer contains the notion of making a sworn statement rebutting a charge. It comes from a prehistoric West and North Germanic compound *andswarō; the first element of this was the prefix *and- ‘against’, related to German ent- ‘away, un-’ and to Greek anti-, source of English anti-; and the second element came from the same source as English swear.

In Old English, the Germanic compound became andswaru (noun) and andswarian (verb) ‘reply’, which by the 14th century had been reduced to answer. The synonymous respond has a similar semantic history: Latin respondēre meant ‘make a solemn promise in return’, hence ‘reply’. And, as another element in the jigsaw, Swedish ansvar means ‘responsibility’ – a sense echoed by English answerable.
=> swear[answer etymology, answer origin, 英语词源]
answer (n.)youdaoicibaDictYouDict
Old English andswaru "an answer, a reply," from and- "against" (see ante) + -swaru "affirmation," from swerian "to swear" (see swear), suggesting an original sense of "make a sworn statement rebutting a charge." A common Germanic compound (cognates: Old Saxon antswor, Old Norse andsvar, Old Frisian ondser, Danish and Swedish ansvar), implying a Proto-Germanic *andswara-. Meaning "a reply to a question," the main modern sense, was present in Old English. Meaning "solution of a problem" is from c. 1300.
answer (v.)youdaoicibaDictYouDict
Old English answarian "to answer;" see answer (n.). Meaning "to respond in antiphony" is from early 15c.; that of "to be responsible for" is early 13c. Related: Answered; answering. The telephone answering machine is from 1961.