Land for native tribe in doubt (11)

I believe the answer is:

reservation

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'doubt' is the definition.
(to have reservations is to have doubts)

I don't understand the rest of the clue.

(Other definitions for reservation that I've seen before include "Putting aside" , "Qualification, proviso" , "Expression of doubt; table booking" , "Expression of doubt (about a claim)" , "misgiving" .)

I've seen this clue in The Times.

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