Tra từ real thing - Từ điển Oxford Advanced Learner 8th

ˈreal tennis 7 [real tennis] BrE NAmE (BrE) (NAmE ˈcourt tennis) (AustralE ˈroyal tennis) noun uncountable
an old form of tennis played inside a building with a hard ball
See also: ↑court tennis ▪ ↑royal tennis

Culture:
Real tennis was originally played by British kings and noblemen (‘real’ is an old form of the word royal), and lawn ↑tennis developed from it. Real tennis has complicated rules. There are very few courts, so not many people play the game.