noun, noun which may take the genitive case particle 'no'
unidentified; unidentifiable; of unknown identity
Used for people, objects, or phenomena whose true nature or identity cannot be determined. Often appears in news, mystery, or speculative contexts.
警察は正体不明の遺体を発見した。
The police found an unidentified body.
夜空に正体不明の光る物体が現れた。
An unidentified glowing object appeared in the night sky.