Translation guide
The English word 'intruder' refers to someone who enters a place without permission, often with hostile or criminal intent. In Japanese, the best translation depends on the context: physical trespassing, digital security, or metaphorical intrusion.
To refer to a person who breaks into a home, office, or restricted area without permission.
The most direct and common translation for a physical intruder. Used in news, security contexts, and everyday speech.
昨夜、侵入者が家に入った。
An intruder entered the house last night.
侵入者を発見したらすぐに警察に通報してください。
If you spot an intruder, please call the police immediately.
A more formal/legal term emphasizing the illegality of the entry. Often used in legal documents or official warnings.
不法侵入者は法律で罰せられます。
Trespassers will be punished by law.
Refers specifically to a burglar or someone who forces their way in, often used in compound words like 押し入り強盗 (burglar).
押し入り強盗が近所で発生した。
A burglary occurred in the neighborhood.
To refer to someone who gains unauthorized access to a computer system or network.
Also used for digital intruders. Context usually makes the meaning clear.
システムに侵入者がアクセスした形跡がある。
There are signs that an intruder accessed the system.
Commonly used for a hacker, especially in media. Can imply malicious intent but not always.
A technical/legal term for someone who performs unauthorized access. Used in IT security contexts.
不正アクセス者がサーバーに侵入した。
An unauthorized access intruder broke into the server.
To describe someone who feels out of place or unwelcome in a social setting or private matter.
Means 'outsider' or 'person not concerned'. Often used when someone is not part of a group and shouldn't be involved.
部外者は立ち入り禁止です。
No trespassing for outsiders. (Intruders not allowed.)
彼は部外者だから、この話には口を出さないでほしい。
He's an outsider, so I wish he wouldn't butt into this conversation.
A literary or formal term for an intruder, often used metaphorically for someone who barges in unexpectedly.
侵入者 (shinnyūsha) strongly implies physical or digital trespassing with potential criminal intent. For a person who is simply unwelcome in a social situation, use 部外者 (bugaisha) or describe the situation differently.
侵入者 is the general term for intruder. 不法侵入者 explicitly adds 'illegal' and is used in legal contexts or formal warnings. In everyday speech, 侵入者 is sufficient.
ハッカーが個人情報を盗んだ。
A hacker stole personal information.
彼は私たちの幸せな家庭に闖入者として現れた。
He appeared as an intruder in our happy home.