Bigwig hesitates and becomes a treacherous person (5)
I believe the answer is:
viper
'a treacherous person' is the definition.
(I've seen this in another clue)
'bigwig hesitates and' is the wordplay.
I cannot really see how this works, but
'bigwig' could be 'vip' (I've seen this in another clue) and 'vip' is located in the answer.
The remaining letters 'er' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'becomes' acts as a link.
Can you help me to learn more?
(Other definitions for viper that I've seen before include "Malicious person" , "Adder" , "treacherous type" , "Deadly-venomous snake" , "Venomous snake, person" .)