Arrive from above and vanquish? (8)
I believe the answer is:
overcome
'vanquish?' is the definition.
(overcoming is a kind of vanquishing)
'arrive from above' is the wordplay.
'arrive' becomes 'come' (synonyms).
'from' becomes 'over' (I can't justify this - if you can you should believe this answer much more).
'above' means one lot of letters go next to another (in a down clue, some letters go above others).
'come' put after 'over' is 'OVERCOME'.
'and' is the link.
Can you help me to learn more?
(Other definitions for overcome that I've seen before include "hammer" , "Succeed in dealing with difficulties" , "Get the better of" , "Come over in order to conquer" , "Emotional" .)