A reply that still carries an oath
In ordinary English, an answer is what you give back: a spoken or written reply, a solution on an exam, a legal filing that meets a complaint point by point. The verb covers the same ground and a little more. You can answer a letter, answer a door, answer for a mistake, or find that a description answers to a face. The origin of the word answer is not a later import from French or Latin. It is native, and the two pieces that make it up are still visible once the spelling is unpacked.
Inherited, not borrowed
English already had the noun in the Old English period, well before 1150, as andswaru, a feminine word for a response or a reply to a question. The matching verb was andswarian or answarian: to make a statement in return. Middle English kept both, usually as answere or andsware for the noun and answeren for the verb. Historical dictionaries treat the item as inherited from Germanic rather than taken from another language in the medieval period. That matters because so many everyday English nouns of this kind did come through French. This one did not.
Independent modern dictionaries agree on the immediate line. Merriam-Webster traces the form from Middle English back to Old English andswaru and notes its kinship with Old Norse andsvar. The American Heritage Dictionary gives the same Old English parent and points the second element toward the Indo-European stem behind swear. The Oxford English Dictionary dates the earliest known use of both noun and verb to Old English.
Against, then a sworn word
The Old English form is a compound. The first element is and-, a prefix meaning against, in return, or opposite. It belongs with a wide Indo-European family whose older sense is front or forehead, the same stock that yields Latin ante and Greek anti. In Germanic it often marks a counter-move: something done facing the other party.
The second element is swaru, an affirmation, built on the same stem as Old English swerian, to swear. Comparative evidence points to a Proto-Germanic noun of the shape andaswaro, a reply, and a matching verb. Put the pieces together and the older picture is not a casual remark but a formal return: a statement made under oath that meets a charge. Etymologists present that legal coloring as a proposed original sense, not as a fact recovered from a dated citation. By the time the word is written in Old English, the everyday meaning reply to a question is already in place. The courtroom shade never vanished entirely. English still uses the noun for a defendant's written response to a complaint, and the verb still means to account for one's conduct.
The deeper ancestry of swear itself is less settled. An older Indo-European account links it to a root meaning to speak, with possible relatives in Slavic words for a quarrel and in Italic forms for a speaker. Other specialists treat the Germanic verb as possibly non-Indo-European, or else closer to Latin verbum, word. That uncertainty sits in the second half of the English compound; it does not undo the analysis of and- plus swaru, which the cognates support.
How the senses widened
Once the word was simply a reply, later English kept adding jobs for it. Around 1300 the noun is recorded for the solution of a problem: not only what you say back, but what closes a difficulty. The verb follows a related path much later; the sense to solve, to find the result of, is dated to the eighteenth century.
Responsibility is older than that. From the early thirteenth century the verb can mean to be accountable, to stand behind something. By the late thirteenth century it can also mean to suffer the consequences. Correspondence and fitness appear in the same medieval window: to answer is to match, to conform, to serve a purpose. From the 1570s the verb can mean to respond in kind by action, not only by speech. Church use adds another layer in the early fifteenth century, when answering can mean taking the other part in antiphony, voice answering voice.
None of these shifts required a new borrowing. They are extensions of the same native verb: return, meet, make good. The later telephone answering machine, so named by the early 1960s, is only a mechanical version of the oldest job, a reply given in the speaker's absence.
Kin across the North Sea
The compound is common Germanic. Old Saxon has antswor, Old Frisian ondser, Old Norse andsvar. Modern Icelandic still has andsvar in the sense of a reply. Danish and Swedish ansvar look like the same word, but their usual meaning has slid toward liability and responsibility, a shift that English made in the verb rather than in the main noun.
German and Dutch took a different route to the same idea. Gothic andavaurd, German Antwort, Dutch antwoord, and Old English andwyrde all mean, more or less, a word in return. They share the against-prefix, but they pair it with word, not with swear. English once had that rival formation too; the swear-compound is the one that survived as the ordinary term. German Schwur, an oath, still shows the other half of the family without the prefix.
A Latin parallel is often noticed without being a source. The classical verb for answering is built on a verb of pledging and assurance, so Roman speech also treated a reply as the return of a solemn engagement. That is a similar habit of mind, not a parent of the English word.
What the silent letter still marks
Modern spelling keeps a w that speech dropped. The letter is the last trace of swaru and of swear. The d of Old English and- disappeared earlier, as andswaru became Middle English answere. What remains in the mouth is a short first syllable and a sibilant; what remains on the page is the old oath. Scandinavian ansvar, now mainly a word for being on the hook, is a useful reminder of that older weight. In English the weight moved into phrases such as answer for, while the bare noun settled on the everyday reply and, after 1300, on the solution you write at the bottom of the page.