People, places and things (5)
I believe the answer is:
nouns
'people places and things' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nouns that I've seen before include "Parts of speech" , "Words referring to person, place or thing" , "Words of particular type" , "Identifying words" , "Words used as names of person, place or thing" .)