A nymphomaniac is a person with an unusually high sex drive. Although it was once a common term, it has since been replaced with the terms sex addiction and hypersexuality. These terms describe individuals who have an addiction to sexual activities, particularly intercourse. Typically, a nymphomaniac has an unusual preoccupation with sex or an obsessive compulsion to have sex. It's not always just about the sexual pleasure either. Nymphomaniacs sometimes feel the need to have sex in an effort to numb bad feelings or simply kill time. More often than not, true nymphomaniacs suffer from other mental or emotional problems such as mood disorders.