KEYSTONE

Central building block at the top of an arch (8)

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

• Quick crossword No 16,522 — 2023-04-19 23:00:29
  24A: Core principle — to Keynes (anag) (8)
• Quick crossword No 16,401 — 2022-11-30 00:00:01
  11A: Central building block at the top of an arch (8)