Not identified; having an unknown or unnamed identity.

Difficult, if not impossible, to identify or name

In an unidentifiable way.

The condition of being unidentifiable

plural of unidentifiability

The quality of being unidentifiable.

That does not serve to identify.

Anything not readily explainable appearing to move through or be suspended in the air, primarily used to refer to objects that seem to be at least of small familiar aircraft size. Abbreviated UFO.

plural of unidentified flying object

plural of unidentified aerial phenomenon