I like Jegutimation's description although I do think a slight rewording would make the definition more specific and straight forward such as: Female characters depicted with any demonic traits, such as horns, thin tails or bat wings.

A formal description: Female characters with horns, tails and wings. They don't necessarily have to have all of these features, but they usually have at least one of them.

a hole still a hole even if it from hell.