Crossword Genius

What overzealous Remainer did is exposed, gathering support (9)

Ross

I believe the answer is:

outstayed

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'what overzealous remainer did' is the definition.
I can't judge whether this defines the answer.

'exposed gathering support' is the wordplay.
'exposed' becomes 'outed' (to out someone is to expose them).
'gathering' means one lot of letters goes inside another (gather can mean to acquire or bring in).
'support' becomes 'stay' (stay is a kind of support).
'outed' enclosing 'stay' is 'OUTSTAYED'.

'is' is the link.

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