Overthrew union, then hung fire (2-5)

I believe the answer is:

up-ended

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'overthrew' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives can occasionally define each other.

'union then hung fire' is the wordplay.
'union' becomes 'U' (common abbreviation as in Trades Union Congress).
'then' means one lot of letters go next to another.
'hung fire' becomes 'pended' (I've seen this in another clue).
'u'+'pended'='UP-ENDED'

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I've seen this clue in the Sydney Morning Herald.

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