Dangerous person overturning barrel and wine box (7)
I believe the answer is:
nutcase
'dangerous person' is the definition.
'nutcase' can be an answer for 'person' (nutcase is a kind of person). I'm not certain of the 'dangerous' bit.
'overturning barrel and wine box' is the wordplay.
'overturning' says the letters should be written in reverse.
'barrel' becomes 'tun' (tun is a kind of barrel).
'and' means one lot of letters go next to another.
'wine box' becomes 'case' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'tun' reversed gives 'nut'.
'nut'+'case'='NUTCASE'
Can you help me to learn more?
(Other definitions for nutcase that I've seen before include "Maybe almond covering" , "He's mad" , "Maniac - shell" , "Eccentric" , "A crazy person like fruit carapace" .)