Flag in west Ireland (4)
I believe the answer is:
tire
'flag' is the definition.
(both can mean to become weary)
'in west ireland' is the wordplay.
'in' indicates a hidden word.
'TIRE' is hidden within 'west ireland'.
(Other definitions for tire that I've seen before include "Exhaust" , "Flag" , "one of four found on Chevrolet?" , "Wear out" , "Become exhausted" .)