The term 'SOCCER's World CUP' refers to the FIFA World CUP, an international SOCCER tournament held every four years. The tournament is contested by the senior men's national teams of the members of the Federation Internationale de Football Association (FIFA), the sport's global governing body. The tournament has been held since 1930, and the most recent edition was held in 2018 in Russia. The three-letter answer to this crossword puzzle is 'CUP'.