If, by "very concrete definition" you mean "party name invented by Mussolini" [1], then yes. Otherwise, absolutely not. I can't tell from your comment which you're trying to imply.
Using the word in reference to a modern political movement is essentially just a lazy, dumb way of flinging a slur that invokes someone bad in history.
[1] Per Britannica: "[Mussolini] took the name of his party from the Latin word "fasces", which referred to a bundle of elm or birch rods (usually containing an ax) used as a symbol of penal authority in ancient Rome."