E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
is the Old English and-swaru, verb and swar-ian or swerian, where And is the preposition = the Latin re in re-spond-eo. (See SWEAR.)
To answer like a Norman, that is, evasively.
We say, in France, Answering like a Norman, which means to give an evasive answer, neither yes nor no.Max ORell; Friend MDonald, ch. v.
To answer its purpose, to carry out what was expected or what was intended. Celsus says, Medicna sæpius respondet, interdum tamen fallit.
To answer the bell is to go and see what it was rung for.
To answer the door is to go and open it when a knock or ring has been given.
In both the last two instances the word is answering to a summons. To swear means literally to affirm something, and to an-swear is to say something by way of rejoinder; but figuratively both the swer and the answer may be made without words.