Term has been (it seems) coined in Italy and has been used by Benito Mussolini for the purposes of his own politics. It fundamentally means some kind of tightly organised group or groups of people.I cannot pretend I know the detail, and there seem to have been more special applications of the term. It was also attributed to Gen. Franco in Spain but there have been the marxist-leninists also involved in Spain which means that you cannot believe anything before having checked out everything thrice.
I was once struck by the Soviets' calling the "German Fascists". I now wonder if there may have been some kind of dislike by the 'Union of the Soviet Socialist Republics' for somebody's 'national socialist workers' party (which was the name of party led by Adolf Schücklgruber alias Hitler formerly Anton Drexler's German Worker's party).
Some 'anti-fascist' organisations in the USA were communist fronts. Why were they 'anti-Fascist' ? Was it Benito Mussolini, or exactly who, that troubled them so much ?
Please note that the arch-criminal (ultra-sneaky criminal ) Bertolt Brecht had circa 1950 claimed that his communist activities in the 1920's were 'anti-Fascist' activities.
Some people, e.g. Elizabeth Bentley, had been in Italy in the 1920's and did not like it indeed, the fascist thing. That was the reason she had later joined the communist racket in the USA, unawares.
Some people might have quite rational exceptions taken to the 'national socialist' (Nazi) movement in Germany, especially after 1933 (the year, more or less, when the Americans were tricked into establishing "normal" relations with the USSR, by the way).
But the fascist Italy 1920's was not the 'national socialist' Germany 1933-45. So, I see some few questions hanging over these developments.
WPT
Bentley, Elizabeth. Title(s) Out of bondage, the story of Elizabeth Bentley. Publisher New York, Devin-Adair, 1951. Paging 3ll p. 22 cm.