Spread covering Irish Rover (6)
I believe the answer is:
pirate
'rover' is the definition.
(I've seen this before)
'spread covering irish' is the wordplay.
'spread' becomes 'pate' (pate is a kind of spread).
'covering' indicates putting letters inside.
'irish' becomes 'IR' (abbreviation for Irish).
'pate' going around 'ir' is 'PIRATE'.
(Other definitions for pirate that I've seen before include "Illegal" , "Copy published material illegally" , "Appropriate stuff" , "He sailed under the Jolly Roger" , "Cornishman maybe" .)