Originally used in opera companies, "prima donna" is Italian for "first lady". Legendarily, these "prima donnas" were often regarded as egotistical, unreasonable and irritable, with a rather high opinion of themselves, not shared by others. Although whether they are truly vainer or more hot-tempered than other singers (or than any other people in the opera houses) is highly debatable, nowadays the term often signifies a vain, obnoxious and temperamental person who, although irritating, cannot be done without.
