Nondescript
/ˈnɒndɪskɹɪpt/
noun
A species or other type of creature that has not been previously described or identified.
An undistinguished, unexceptional person or thing.
An unmarked police car.
adjective
Not described (in the academic literature).
Without distinguishing qualities or characteristics.
“He drove a nondescript silver sedan.”
Synonyms: undescribed, unidentified, unexceptional