Prohibit Eurovision winner from using neckerchief (7)
I believe the answer is:
bandana
'using neckerchief' is the definition.
'bandana' can be an answer for 'neckerchief' (bandana worn around the neck). I'm not sure about the 'using' bit.
'prohibit eurovision winner' is the wordplay.
'prohibit' becomes 'ban' (banning is a kind of prohibiting).
'eurovision winner' becomes 'dana' (I can't justify this - if you can you should give a lot more credence to this answer).
'ban'+'dana'='BANDANA'
'from' acts as a link.
Can you help me to learn more?
(Other definitions for bandana that I've seen before include "Type of scarf" , "Brightly coloured neckerchief" , "Spotted square" , "Large coloured neckerchief" , "Coloured square worn around the head or neck" .)