Translation guide
Describes actions, movements, or qualities that are quiet, secretive, and intended to avoid detection. In Japanese, this concept is expressed through adjectives, verbs, and descriptive phrases that emphasize quietness, secrecy, or slyness.
Describing a person, animal, or action that is deliberately quiet and careful, often for sneaking or not being noticed.
An adverb meaning 'secretly' or 'stealthily', used for actions done quietly to avoid being seen or heard. Very common and natural.
彼はこっそり部屋を抜け出した。
He stealthily slipped out of the room.
猫がこっそり近づいてきた。
The cat approached stealthily.
A noun meaning 'stealthy steps' or 'tiptoeing'. Often used with で to describe moving quietly.
忍び足で廊下を歩いた。
I walked down the hallway with stealthy steps.
A phrase meaning 'without making a sound'. Used to describe doing something quietly.
音を立てずにドアを閉めた。
I closed the door stealthily, without making a sound.
An adverb meaning 'secretly' or 'in secret'. Slightly more formal or literary than こっそり, often used for plans or feelings.
彼はひそかに計画を進めていた。
He was stealthily advancing his plan.
Referring to military technology like stealth aircraft that avoid radar detection.
A loanword from English, used specifically for stealth technology (e.g., stealth fighters).
ステルス戦闘機はレーダーに映りにくい。
Stealth fighters are hard to detect on radar.
A noun meaning 'stealth' or 'secrecy', sometimes used in military contexts but more often for ninja or covert operations. Can be technical.
Describing behavior that is sneaky, underhanded, or done in a way that feels dishonest.
An adverb implying sneaky, furtive behavior, often with a negative nuance. Used for actions that seem suspicious.
彼はこそこそと何かを隠した。
He stealthily hid something, looking suspicious.
A phrase meaning 'behind the scenes' or 'in secret', often implying underhandedness.
彼は陰で悪口を言っている。
He's stealthily badmouthing people behind their backs.
こっそり is neutral or slightly positive (like sneaking a surprise), while こそこそ has a negative, suspicious feel (like hiding something bad). Use こっそり for general 'stealthy' actions.
こっそりプレゼントを置いた。
I stealthily left a present.
こそこそと逃げ出した。
He sneaked away guiltily.
隠密行動
stealth operation