Stayed in bed longer at some expense (6)
I believe the answer is:
outlay
'some expense' is the definition.
(synonyms)
'stayed in bed longer' is the wordplay.
I cannot really see how this works, but
'bed' could be 'lay' (I've seen this before) and 'lay' is found in the answer.
The remaining letters 'out' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'at' acts as a link.
Can you help me to learn more?
(Other definitions for outlay that I've seen before include "Money paid out" , "Expenditure on something" , "Money expended" , "Amount spent on something" , "Expenditure of money" .)