KNOCKER

It bangs on a door (7)

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

• Quick crossword No 16,125 — 2022-01-12 00:00:32
  10A: Door rapper (7)
• Quick crossword No 15,912 — 2021-05-06 23:00:20
  14D: Device for rapping (7)
• Quick crossword No 15,642 — 2020-06-24 23:00:28
  14D: It bangs on a door (7)