Illegally assist a venture (4)

I believe the answer is:

abet

'illegally assist' is the definition.
(I've seen this in another clue)

'a venture' is the wordplay.
'venture' becomes 'bet' (bet is a kind of venture).
'a'+'bet'='ABET'

(Other definitions for abet that I've seen before include "Incite or encourage" , "Aid in offence" , "Help in wrongdoing" , "Encourage or assist (someone) to commit crime" , "Help a criminal" .)

I've seen this clue in The Everyman puzzle in The Observer.

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