Animal, vegetable or mineral
I believe the answer is:
noun
'animal vegetable or mineral' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for noun that I've seen before include "Naming word (grammar)" , "Substantive word" , "Word identifying people, things, etc" , "Part of speech identifying a person, place or thing" , "Word that refers to a person, place or thing" .)