Ostentatious, indicate violent outburst (10)

I believe the answer is:

flashpoint

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'violent outburst' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'ostentatious indicate' is the wordplay.
'ostentatious' becomes 'flash' (I've seen this before).
'indicate' becomes 'point' (synonyms).
'flash'+'point'='FLASHPOINT'

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(Other definitions for flashpoint that I've seen before include "moment of emergency" , "Moment when hostility flares up" .)

I've seen this clue in The Daily Express.

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