PENTAGON

Headquarters of the US Defense Department (8)

Solution has appeared in 3 crosswords (2 across and 1 down):

• Quick crossword No 16,615 — 2023-08-06 23:00:24
  10D: US Department of Defense (8)
• Quick crossword No 16,214 — 2022-04-25 23:00:50
  17A: Five-sided shape (8)
• Quick crossword No 15,769 — 2020-11-20 00:00:25
  16A: Headquarters of the US Defense Department (8)