Last word from revolutionary with anger about nothing (7)
I believe the answer is:
cheerio
'last word' is the definition.
(word for goodbye)
'revolutionary with anger about nothing' is the wordplay.
'revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'with anger' becomes 'ire' (ire is intense rage. I am not sure about the 'with' bit.).
'about' says the letters should be written in reverse.
'nothing' becomes 'o' (looks like zero - 0).
'ire' backwards is 'eri'.
'che'+'eri'+'o'='CHEERIO'
'from' acts as a link.
(Other definitions for cheerio that I've seen before include "good health" , "Bye-bye" , "A final word" , "See you" , "Farewell - drinking toast" .)