Prevent everyone supporting Nottingham team? (9)
I believe the answer is:
forestall
'prevent' is the definition.
(I know that prevent can be written as forestall)
'everyone supporting nottingham team?' is the wordplay.
'everyone' becomes 'all' (all people).
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'nottingham team?' becomes 'forest' (I am not sure about this - if you are sure you should believe this answer much more).
'all' after 'forest' is 'FORESTALL'.
Can you help me to learn more?
(Other definitions for forestall that I've seen before include "Anticipate" , "Obstruct by taking advance action" , "Hinder by anticipation" , "Take action before" , "Prevent by taking advance action" .)