Answer

a spoken or written reply or response to a question, request, letter, etc.:
he sent an answer to my letter promptly.
a correct response to a question asked to test one’s knowledge.
an equivalent or approximation:
a singing group that tried to be the french answer to the beatles.
an action serving as a reply or response:
the answer was a volley of fire.
a solution to a problem, especially in mathematics.
a reply to a charge or accusation.
law. a pleading in which a party responds to his or her opponent’s statement of position, especially the defendant’s reply to the plaintiff’s complaint.
music. the entrance of a fugue subject, usually on the dominant, either slightly altered or transposed exactly after each presentation in the tonic.
to speak or write in response; make answer; reply.
to respond by an act or motion:
he answered with a nod. the champion answered with a right to the jaw.
to act or suffer in consequence of (usually followed by for).
to be or declare oneself responsible or accountable (usually followed by for):
i will answer for his safety.
to be satisfactory or serve (usually followed by for):
his cane answered for a baseball bat.
to conform; correspond (usually followed by to):
the prisoner answered to the description issued by the police.
to speak or write in response to; reply to:
to answer a person; to answer a question.
to act or move in response to:
answer the doorbell. we answered their goal with two quick goals of our own.
to solve or present a solution of.
to serve or fulfill:
this will answer the purpose.
to discharge (a responsibility, claim, debt, etc.).
to conform or correspond to; be similar or equivalent to:
this dog answers your description.
to atone for; make amends for.
to reply or respond favorably to:
i would like to answer your request but am unable to do so.
answer back, to reply impertinently or rudely:
well-behaved children do not answer back when scolded.
answer the helm, nautical. (of a vessel) to maneuver or remain steady according to the position of the rudder.
contemporary examples

facebook’s answer to its critics is: pay no attention to the carping.
facebook’s dilemma: invade privacy or go bust david frum may 23, 2012

there is never going to be a proof that g-d is there to answer that need.
francis spufford on how atheists put religion through all the wrong tests francis spufford october 12, 2013

perhaps the answer is as simple as why people loved american idol so much for so many years.
why i loathe glee jace lacob september 28, 2010

but the new york city ballet seems to have found the answer: valentino.
how high fashion saved the ballet raquel laneri october 12, 2014

in other words, his childhood question to his mother has by definition no answer — and furthermore, must have none.
how hitch & amis discovered evil in my house peter foges september 27, 2014

historical examples

he was not prepared with any answer, though he hotly resented every word of her accusation.
within the law marvin dana

he did apply, and at the end of a month, no answer had been returned to his communication.
blackwood’s edinburgh magazine, no. 327 various

“i don’t know,” i left anthony to answer; wondering what he would say.
it happened in egypt c. n. williamson

and thus, as mr. lovelace thought fit to take it, had he his answer from my sister.
clarissa, volume 1 (of 9) samuel richardson

and if they are asked why, they answer: ‘there are three great evils in our district!’
the chinese fairy book various

noun
a reply, either spoken or written, as to a question, request, letter, or article
a reaction or response in the form of an action: drunkenness was his answer to disappointment
a solution, esp of a mathematical problem
(law)

a party’s written reply to his opponent’s interrogatories
(in divorce law) the respondent’s written reply to the pet-tion

a musical phrase that follows the subject of a fugue, reproducing it a fifth higher or a fourth lower
verb
(when transitive, may take a clause as object) to reply or respond (to) by word or act: to answer a question, he answered, to answer the door, he answered that he would come
(transitive) to reply correctly to; solve or attempt to solve: i could answer only three questions
(intransitive) usually foll by to. to respond or react (to a stimulus, command, etc): the steering answers to the slightest touch
(transitive) to pay off (a debt, obligation, etc); discharge
when intr, often foll by for. to meet the requirements (of); be satisfactory (for); serve the purpose (of): this will answer his needs, this will answer for a chisel
when intr, often foll by to. to match or correspond (esp in the phrase answer (or answer to) the description)
(transitive) to give a defence or refutation of (a charge) or in (an argument)
n.

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 reb-tting a charge.” a common germanic compound (cf. 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.
v.

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.

answer back
answer for
answer to

also see:

know all the answers
take no for an answer