The setter's weight is appropriate! (7)
I believe the answer is:
impound
'is appropriate' is the definition.
(I've seen this before)
'the setter's weight' is the wordplay.
'the setter's' becomes 'im' (I've seen this in other clues).
'weight' becomes 'pound' (pound is a kind of weight**).
'im'+'pound'='IMPOUND'
(Other definitions for impound that I've seen before include "Confiscate" , "put cordon round" , "Seize and take custody of (items)" , "Take legal possession of" , "Seize and take into legal custody" .)