QUARTERLY

At three-month intervals (9)

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

• Quick crossword No 16,737 — 2023-12-28 00:00:19
  7D: Every three months (9)
• Quick crossword No 16,094 — 2021-12-06 00:00:08
  19A: At three-month intervals (9)