Word that can be proper or common (4)

I believe the answer is:

noun

(Other definitions for noun that I've seen before include "Substantive word" , "Type of word" , "Word referring to person, place or thing" , "Word identifying person, place or thing" , "Part of speech identifying a person, place or thing" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.