State purpose ultimately thwarted (3)
I believe the answer is:
goa
'state' is the definition.
(Indian state)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for goa that I've seen before include "Indian state, former Portuguese colony" , "Indian Territory" , "gazelle?" , "Former Portuguese colony on India's west coast" , "West coast Indian state" .)