down and dirty

Unfair, vicious; also, coarse, explicit about unpleasant mat- ters. The first usage of this colloquialism dates from the mid-1900s, as in “The neighbors were furious about the new ordinance and waged a real down and dirty fight.” The second surfaced a decade or two later, as in the film entitled Down and Dirty (1976), a black comedy about a depraved family whose inter- ests include adultery, murder, revenge, and incest