Last character used to symbolise the resistance? (5)

I believe the answer is:

omega

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'last character' is the definition.
(Greek alphabet)

I don't understand how the remainder of the clue works.

(Other definitions for omega that I've seen before include "Last letter of the Greek alphabet" , "Art of story-telling by body movement" , "Greek finalist" , "Final outcome" , "Foreign character" .)

I've seen this clue in The Times.

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