Sex between a guy, and four (or more girls) girls. Or a girl and four (or more) guys.
Not an considered an orgy, because an orgy is equal or almost an equal amount of people of the opposite sexes. Or more then four people of the same sex.
Doug: My friend just called me, and apparently he had a moresome last night.
Tova: And you believe him?
Doug: Well, I normally wouldn't, but one of the girls involved called me to tell me about it too.