Trim mould around joints (9)
I believe the answer is:
shipshape
'trim' is the definition.
('shipshape' can be a synonym of 'trim')
'mould around joints' is the wordplay.
'mould' becomes 'shape' ('shape' can be a synonym of 'mould'**).
'around' indicates putting letters inside.
'joints' becomes 'hips' (hip is a kind of joint).
'shape' placed around 'hips' is 'SHIPSHAPE'.
(Other definitions for shipshape that I've seen before include "Hash pipes may be in good order - like sailor?" , "Neat and trim" , "In good order, like well-dressed sailor?" , "fashionable in Bristol" , "Neat, orderly" .)