Opt out from employment and go to bed (6)
I believe the answer is:
retire
'go to bed' is the definition.
(synonyms)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for retire that I've seen before include "Withdraw - give up work - go to bed" , "Give up working and go to bed" , "Quit work, take pension" , "climb the stairs" , "Leave work; go back" .)