Island's border crossing showing native loyalty (9)
I believe the answer is:
tribalism
'native loyalty' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'island's border crossing' is the wordplay.
'island's' becomes 'Bali's' (Indonesian island).
'border' becomes 'trim' (I've seen this before).
'crossing' indicates putting letters inside.
'balis' inserted into 'trim' is 'TRIBALISM'.
'showing' is the link.
Can you help me to learn more?
(Other definitions for tribalism that I've seen before include "allegiance to group" , "divisive tendency" , "Clannishness" , "Failure to transcend clan loyalty" , "ethnic customs" .)