Smell a new person (5)
I believe the answer is:
human
'person' is the definition.
(I know that person can be written as Human)
'smell a new' is the wordplay.
'smell' becomes 'hum' (something with a bad smell is 'humming').
'new' becomes 'n' (abbreviation as in New Testament NT).
'hum'+'a'+'n'='HUMAN'
(Other definitions for human that I've seen before include "Of the species of homo sapiens" , "Man, woman or child" , "Relating to a person" , "Being that's apt to err?" , "Like people" .)