The arch in a girlsback when she pushes out her ass and tits at the same time in an attempt to look sexy or slutty. The resulting arch is a slutback. Some arches are natural, others may be forced.
slutfish- (noun) a combination of the words "selfish" and "slut" intended to describe two parts of a singular person's personality and/or outward appearance. ie- a whore who is a selfish asshole.
My aunt is marrying someone closer to her daughter's age than her own, and expects her entire family to pay for everything for her THIRD wedding, including a trip to the caribbean which they are not invited to... what a fucking slutfish.