Succeeding by stopping ensnarement plan (4)
I believe the answer is:
next
'succeeding' is the definition.
(I know that succeeding can be written as next)
'by stopping ensnarement plan' is the wordplay.
'by' becomes 'x' (e by 4 is e x 4).
'stopping' is an insertion indicator (stopping can mean blocking a gap).
'ensnarement plan' becomes 'net' (I can't explain this - if you can you should believe this answer much more).
'x' placed into 'net' is 'NEXT'.
Can you help me to learn more?
(Other definitions for next that I've seen before include "Closest" , "Coming nearest in time or sequence" , "Nearest in space or position" , "Retailer" , "First in line" .)