Refuse to sleep across river (5)
I believe the answer is:
dross
'refuse' is the definition.
(thesaurus)
'sleep across river' is the wordplay.
'sleep' becomes 'doss' (I've seen this before).
'across' is an insertion indicator.
'river' becomes 'r'.
'doss' placed around 'r' is 'DROSS'.
'to' acts as a link.
(Other definitions for dross that I've seen before include "Scum on molten metals" , "Rubbish; impurities" , "Slag!" , "Anything worthless" , "Lees" .)