One held by facial feature, sound (5)
I believe the answer is:
noise
'sound' is the definition.
(noise is a kind of sound)
'one held by facial feature' is the wordplay.
'one' becomes 'i' (Roman numeral).
'held by' indicates putting letters inside.
'facial feature' becomes 'nose' (I've seen this before).
'i' placed inside 'nose' is 'NOISE'.
(Other definitions for noise that I've seen before include "Unstructured sound" , "Fuss" , "Sound, disagreeable perhaps" , "Loud sound; bruit" , "Sound of any kind" .)