Stolen goods suitable at first to move to and fro (4)
I believe the answer is:
swag
'stolen goods' is the definition.
(I've seen this before)
'suitable at first to move to and fro' is the wordplay.
'at first' says to take the initial letters.
'to move to and fro' becomes 'wag' (I've seen this in another clue).
The first letter of 'suitable' is 's'.
's'+'wag'='SWAG'
(Other definitions for swag that I've seen before include "Burglar's spoils" , "Ill-gotten gains" , "stuff stolen" , "goods from burglary" , "Goods taken by burglar" .)