lacking distinctive or interesting qualities; dull

of nondescript appearance and personality

orig, belonging to no particular class or kind; hard to classify; neither one thing nor another

a nondescript animal

a person or thing of unknown type

What it was, whether bear or man or monkey, I could in no wise tell … Behind me the murderers, before me this lurking nondescript — Stevenson

a person or thing not worth classifying

ranging from the landlord to the lowest stable nondescript — Dickens

It was the old-fashioned wheeled nondescript belonging to the captain, and Thomasin sat in it alone — Hardy