Translation guide
Describes actions or people that are secretive, underhanded, or done in a way that avoids being noticed, often with a negative connotation.
Describing a person or action that is dishonest, cunning, and not straightforward.
The most common and versatile word for 'sneaky' in the sense of being cunning or unfair. Can describe both people and actions.
Describing an action done quietly or secretly to avoid detection, without necessarily implying dishonesty.
Informal ways to call someone sneaky or a sneak.
A common phrase meaning 'sly/cunning guy'. ずる賢い combines ずるい (sneaky) and 賢い (clever).
あいつは本当にずる賢いやつだ。
That guy is a real sneaky bastard.
ずるい focuses on unfairness or cunning, often with moral judgment. こそこそした describes furtive, guilty-looking behavior. こっそり is a neutral adverb for doing something secretly without negative implications.
ずるいことをするな。
Don't do sneaky (unfair) things.
こそこそしないで堂々としなさい。
Stop being sneaky and be upfront.
こっそりプレゼントを置いた。
I secretly left a present.
He passed the exam in a sneaky way.
ずるいよ！ずるいって！
That's sneaky! So unfair!
A more formal or literary term for 'cunning' or 'sly'. Often used in writing or to describe a crafty scheme.
彼は狡猾な手口で金をだまし取った。
He swindled money through a sneaky scheme.
Describes sneaky, furtive behavior, like doing something secretly or behind someone's back. Often implies guilt or shame.
こそこそした態度が怪しい。
His sneaky behavior is suspicious.
An adverb meaning 'secretly' or 'stealthily'. Used for actions done without others noticing, like sneaking a snack or leaving quietly.
彼はこっそりと部屋を抜け出した。
He sneaked out of the room.
こっそりお菓子を食べた。
I sneaked a snack.
Literally 'with stealthy steps', used for moving quietly like a ninja. More physical and deliberate than こっそり.
忍び足で近づいた。
I approached with sneaky steps.
Literally 'sneak thief', a petty thief who steals by sneaking around. Can be used figuratively for someone who does things behind your back.
彼はコソ泥みたいに人のアイデアを盗む。
He steals people's ideas like a sneak thief.