Definition of Antifa in US English:

Antifa

noun

  • treated as singular or plural A political protest movement comprising autonomous groups affiliated by their militant opposition to fascism and other forms of extreme right-wing ideology.

    ‘Saturday's rally had the support of Antifa, whose sworn enemy is the far right’
    as modifier ‘riot police snatched black-clad Antifa protesters and arrested them’

Origin

1940s (with reference to opposition to fascism in Germany during and immediately after the Second World War): German, shortened from Antifaschismus ‘anti-fascism’ and antifaschistisch ‘anti-fascist’.

Pronunciation