Describing someone crafty, sly, or underhanded; behaving in a deceitful or treacherous manner.
彼は陰険な手口で会社の金を横領していた。
He embezzled company money using underhanded methods.
あの上司は陰険だから、言葉に気をつけたほうがいい。
That boss is sly, so you should be careful about what you say.
陰険な陰口を言われていると感じたら、早めに対処したほうがいい。
If you feel people are whispering maliciously about you, it's best to address it early.
彼女は表向きは優しいが、どこか陰険なところがある。
She seems kind outwardly, but there's something sly about her.
Having a sinister or creepy appearance; conveying a menacing or ominous look.
その建物の陰険な外観が夜になるとさらに怖く見える。
The building's sinister appearance looks even scarier at night.
彼の笑顔にはどこか陰険な影があって、信用できなかった。
There was something sinister behind his smile, so I couldn't trust him.