McKinley releases my overseas capital (6)
I believe the answer is:
nickel
'capital' is the definition.
The answer and definition can be both related to property as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for nickel that I've seen before include "One twentieth of a US dollar" , "Five-cent piece in the US" , "US 5 cents" , "very little money" , "Five-cent coin (US)" .)