卑怯ひきょう
hikyō

Noun
na-Adjective

1. cowardly; craven

Noun
na-Adjective

2. unfair; mean; sneaky; dirty; dastardly

そんなふうにうなんて卑怯ひきょうだ。
sonnafūni iunante hikyōda.
It's mean of you to talk that way.