Better to cover worker retiring for a short sleep (6)
I believe the answer is:
catnap
'a short sleep' is the definition.
('catnap' can be a synonym of 'short sleep')
'better to cover worker retiring' is the wordplay.
'better' becomes 'cap' (I've seen this before**).
'to cover' means one lot of letters goes inside another.
'worker' becomes 'ant' (worker is a type of ant).
'retiring' is a reversal indicator.
'ant' reversed gives 'tna'.
'cap' going around 'tna' is 'CATNAP'.
'for' is the link.
(Other definitions for catnap that I've seen before include "For a rest" , "Brief doze" , "Short sleep" , "Forty winks (for moggy?)" , "go out briefly" .)