Retire (4,2)
'retire?' is the definition.
('hit the hay' can be a synonym of 'retire')
This is all the clue.
(Other definitions for hit the hay that I've seen before include "Turn in" , "Crash" , "Go to bed (informal)" , "(retired)" , "Retire to bed (informal)" .)
'retire' is the definition.
(turn in can mean to retire or go to bed)
This is all the clue.
(Other definitions for turn in that I've seen before include "Go to bed, changing direction" , "Hit the hay" , "rat on" , "Surrender" , "Informally, go to bed or hand over" .)
'retire' is the definition.
(bowing out is a kind of retiring)
This is the entire clue.
(Other definitions for bow out that I've seen before include "Withdraw from a situation" , "Retire from the scene with bodily gesture of acknowledgement?" , "Retire gracefully" , "Exit; retire" , "What a string player often gets" .)