Rationale designed for person prone to distancing? (9)

I believe the answer is:

alienator

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'person prone to distancing?' is the definition.
I can't judge whether this definition defines the answer.

'rationale designed' is the wordplay.
'designed' is an anagram indicator (designed with the letters).
'rationale' anagrammed gives 'ALIENATOR'.

'for' acts as a link.

Can you help me to learn more?

(Other definitions for alienator that I've seen before include "Off-putting type" , "one who repels" , "Causer of estrangement" .)

I've seen this clue in The Times.

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