Stop working and hit the sack (6)
I believe the answer is:
retire
This clue is a double definition.
'stop working' is the first definition.
(I've seen this before)
'hit the sack' is the second definition.
('retire' can be a synonym of 'hit the sack')
'and' is the link.
(Other definitions for retire that I've seen before include "Get your head down" , "Withdraw - give up work - go to bed" , "end occupation" , "Quit work, take pension" , "Go to bed or quit work for good" .)