Definition of red belt in English:

red belt

Pronunciation /ˌrɛd ˈbɛlt/

noun

  • 1Politics
    An area under communist control or influence. An area of communist strength or electoral control within a democratic country, especially the outer suburbs of Paris.

  • 2= Soviet bloc . rare (now historical).

  • 3A belt marking the attainment of a certain degree of proficiency in judo and certain other martial arts; especially one denoting a high degree of mastery.

Origin

1920s. From red + belt.