COPPER

Police officer (slang) (6)

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

• Quick crossword No 15,893 — 2021-04-14 23:00:19
  14A: Metal, Cu (6)
• Quick crossword No 15,699 — 2020-08-30 23:00:51
  14A: Metal, Cu (6)
• Quick crossword No 15,489 — 2019-12-30 00:00:51
  15D: Police officer (slang) (6)