Soldier laid back in beret for a quick snooze (6)
I believe the answer is:
catnap
'a quick snooze' is the definition.
(a catnap is a quick sleep)
'soldier laid back in beret' is the wordplay.
'soldier' becomes 'ant' (soldier ant is a type of ant).
'laid back' shows that the letters should be reversed in order.
'in' is an insertion indicator.
'beret' becomes 'cap' (beret is a type of cap).
'ant' backwards is 'tna'.
'tna' placed within 'cap' is 'CATNAP'.
'for' is the link.
(Other definitions for catnap that I've seen before include "(Tom's) snooze?" , "For a rest" , "Forty winks (for moggy?)" , "Short sleep" , "little snooze" .)