A bit like audible tranquillity (5)
I believe the answer is:
piece
'a bit' is the definition.
('piece' can be a synonym of 'bit')
'audible tranquillity' is the wordplay.
'audible' shows a homophone (sound like).
'tranquillity' becomes 'peace' (peace is a kind of tranquillity).
'peace' is a homophone of 'PIECE'.
'like' is the link.
(Other definitions for piece that I've seen before include "American gun" , "artefact" , "Portion, coin, item" , "wedge a > bit" , "Single article" .)