STRATUM

Bed of sedimentary rock (7)

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

• Quick crossword No 16,539 — 2023-05-09 23:00:02
  15D: Layer (7)
• Quick crossword No 15,377 — 2019-08-19 23:00:21
  23A: Bed of sedimentary rock (7)