GRANDSLAM

Winning all four major tennis championships in the same calendar year (5,4)

Solution has appeared in 2 crosswords (2 across and 0 down):

• Quick crossword No 16,649 — 2023-09-14 23:00:44
  21A: Winning all 13 tricks in a hand of bridge (5,4)
• Quick crossword No 16,217 — 2022-04-28 23:00:24
  1A: Winning all four major tennis championships in the same calendar year (5,4)