Finish, as do Gog and Magog (6)
I believe the answer is:
ending
'finish' is the definition.
(I know that finish can be written as ending)
'as do gog and magog' is the wordplay.
I cannot quite understand how this works, but
'as' could be 'in' (I've seen this in other clues) and 'in' is located in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ending that I've seen before include "Closing down" , "Finishing" , "Armageddon?" , "terminal" , "Termination, conclusion" .)