I love very big problem coming up for dictator (9)
I believe the answer is:
mussolini
'for dictator' is the definition.
(Benito Mussolini, Italian dictator)
'i love very big problem coming up' is the wordplay.
'love' becomes 'nil' (love and nil mean zero in cricket and football).
'very big' becomes 'os' (abbreviation for outsize).
'problem' becomes 'sum' (arithmetic problem).
'coming up' says the letters should be written backwards.
'i'+'nil'+'os'+'sum'='inilossum'
'inilossum' back-to-front is 'MUSSOLINI'.
(Other definitions for mussolini that I've seen before include "Italian World War Two leader" , "WW 2 Italian leader" , "Word War Two Italian dictator" , "Italian WW2 dictator" , "Wartime leader" .)