Vessel returns, carrying gold for island country (5)
I believe the answer is:
nauru
'island country' is the definition.
'Nauru' can be an answer for 'country' (Nauru is an example). I'm not sure about the 'island' bit.
'vessel returns carrying gold' is the wordplay.
'vessel' becomes 'urn' (urn is a kind of vessel).
'returns' says the letters should be written in reverse.
'carrying' indicates putting letters inside.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'urn' backwards is 'nru'.
'nru' enclosing 'au' is 'NAURU'.
'for' is the link.
Can you help me to learn more?
(Other definitions for nauru that I've seen before include "[OCEANIA] location" , "Pacific republic, formerly Pleasant Island" , "SW Pacific republic" , "Pacific island country" , "little nation" .)