Set about Ben for taking Joe in (5)
I believe the answer is:
begin
'set about' is the definition.
(synonyms)
'ben for taking joe in' is the wordplay.
I cannot quite understand how this works, but
'joe' could be 'gi' (GI Joe) and 'gi' is found within the answer.
The remaining letters 'ben' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for begin that I've seen before include "Commence" , "Israeli prime minister who shared the Nobel Peace Prize with President Sadat" , "Israeli prime minister and Nobel Peace Prize winner, d. 1992" , "Initiate" , "Found" .)