Note: Do not rely on this information. It is very old.
Euphemism
Euphemism (Gk. en, well; phemi, I speak) - to speak well of, to speak fair - that figure of speech in which something is called by a fair name instead of a disagreeable or uncomplimentary one. The Greeks called the stormy Black Sea the Euxine (" kind to strangers"), the Furies the Eumenides (" well-wishers"); so the Scots will call the fairies the Good People.