Translation guide
Describes something whose identity, origin, or nature is unknown or not yet determined. Japanese uses different expressions depending on whether you're talking about a person, object, phenomenon, or formal status.
To say that something or someone has not been identified, often in news, reports, or formal contexts.
Literally 'identity unknown'. Commonly used for unidentified persons (e.g., bodies, suspects, patients).
身元不明の遺体が見つかった。
An unidentified body was found.
Emphasizes that the true nature or identity is unknown, often with a nuance of mystery or suspicion. Used for people, creatures, or phenomena.
正体不明の生物が目撃された。
An unidentified creature was sighted.
Means 'unconfirmed' or 'unidentified'. Often used in compounds like 未確認飛行物体 (UFO).
未確認の情報が流れている。
Unconfirmed information is circulating.
To refer to someone whose name or identity you don't know in everyday conversation.
Literally 'don't know who it is'. Natural in casual speech.
誰だかわからない人が家の前に立ってた。
An unidentified person was standing in front of the house.
Means 'unknown' or 'unfamiliar' (person). Slightly literary but common.
見知らぬ男が話しかけてきた。
An unidentified man spoke to me.
To describe something seen or detected that cannot be identified, like a flying object or signal.
Standard term for UFO. Often abbreviated as UFO (ユーフォー) in casual contexts.
未確認飛行物体が目撃された。
An unidentified flying object was sighted.
General phrase for an unidentified object, not necessarily flying.
海で正体不明の物体が浮かんでいた。
An unidentified object was floating in the sea.