Sound of hooter about one (5)
I believe the answer is:
noise
'sound' is the definition.
(noise is a kind of sound)
'hooter about one' is the wordplay.
'hooter' becomes 'nose' (I've seen this before).
'about' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'nose' going around 'i' is 'NOISE'.
'of' acts as a link.
(Other definitions for noise that I've seen before include "Excessive sound" , "Loud or unpleasant sound" , "Din, cacophony" , "Clamour" , "Hubbub" .)