Ensign’s delight about pounds received (5,5)
I believe the answer is:
jolly roger
'ensign's' is the definition.
(thesaurus)
'pounds received' is the wordplay.
'pounds' becomes 'jolly' (I can't explain this - if you can you should give a lot more credence to this answer).
'received' becomes 'roger' (I've seen this before).
'jolly'+'roger'='JOLLY ROGER'
'delight about' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for jolly roger that I've seen before include "standard not welcomed in the main" , "Pirates' flag" , "standard for boarders?" , "In the main a fearful sight" , "Pirate flag" .)