Fixed vice becomes prevalent (6)

I believe the answer is:

setsin

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'prevalent' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'fixed vice' is the wordplay.
'fixed' becomes 'set' (both can mean decided or determined).
'vice' becomes 'sin'.
'set'+'sin'='SETSIN'

'becomes' is the link.

Can you help me to learn more?

I've seen this clue in The Irish Independent.

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