性しょう悪わる

na-adjective, noun

ill-natured; bad-tempered; mean-spirited

Describes a person's fundamentally unpleasant or malicious character. Often used in the phrase 性悪説 (せいあくせつ) meaning 'theory of innate human evil', but the reading しょうわる is more common for the standalone adjective/noun.

• 彼かれは性しょう悪わるだから、あまり信しん用ようしないほうがいい。

  He's ill-natured, so you'd better not trust him too much.

• あの子こは性しょう悪わるで、すぐに意い地じ悪わるをする。

  That kid is mean-spirited and quickly does nasty things.