Racket one found in trunk? (5)
I believe the answer is:
noise
'racket' is the definition.
(racket can mean a loud noise)
'one found in trunk?' is the wordplay.
'one' becomes 'i' (Roman numeral).
'found in' means one lot of letters goes inside another.
'trunk?' becomes 'nose' (an elephant's trunk is its nose).
'i' put within 'nose' is 'NOISE'.
(Other definitions for noise that I've seen before include "Commotion" , "Din, cacophony" , "Clatter" , "Unstructured sound" , "Excessive sound" .)