euphonous. (archaic) adjective form of euphony.
why euphonous? euphony comes from two different greek roots - 'eu' meaning good and 'phony' meaning sound. 'eu' appears in many english words, words like both euphoria and eugenics and euphemism.
the 'eu' stem may mean good, but that does not mean anything. eugenics, for example, 'good birth', is not a good birth at all, with a long and bloody history. what, then, gives us the right to euphony? what expresses euphony?
a perfect chord, maybe.