Why are the 4 biggest tournaments called 'grand slams'? What does that even mean? 'A grand slam tournament'. It sounds nonsensical.
the four big tournaments are actually called the majors, as in major tournaments. The grand slam is winning all four in a calendar year. Somehow people got used to calling each major a grand slam. The actual term 'grand slam' originated from the card game - bridge. The winning of all the tricks during the play of one hand is called a grand slam. The term was brought from the card table to sports by a sports reporter when it was used to refer to Budge in 1938. Budge was the first player to win all the major singles tennis competitions in one season and it was widely reported as his 'grand slam'.