The original term for a player winning all four of the major tennis Championships (the Australian Open
, French Open
and US Open
during the same calendar year.
Recently, this term has been bastardized by the media and others to include bogus combinations such as "non-calendar year Grand Slam", "career Grand Slam" etc - but none equals the difficulty or rarity of achieving the only true Grand Slam.
Hence, it has only been achieved in Singles tennis play by two men and three women: Don Budge and Rod Laver (twice), and Brinker, Court and Steffi Graf, respectively.
Other sports use the term to portray winning all of the major championships in one calendar year (ie golf). In Baseball
it refers to hitting a bases-loaded home run
and in Contract Bridge it refers to winning all tricks in one hand.
Rod Laver is the only player in history to win the Tennis Grand Slam twice.