Had coin in change for part of south-east Asia (9)
I believe the answer is:
indochina
'for part of south-east asia' is the definition.
(historical geographical term)
'had coin in change' is the wordplay.
'change' indicates anagramming the letters.
'had'+'coin'+'in'='hadcoinin'
'hadcoinin' anagrammed gives 'INDOCHINA'.
(Other definitions for indochina that I've seen before include "Peninsula of south-eastern Asia" , "Vietnam etc" , "Southeast Asian peninsula -- I hand coin (anag)" , "South-east Asian region" , "peninsular area" .)