ZITHER

Metal-stringed soundbox (6)

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

• Quick crossword No 16,292 — 2022-07-25 23:00:48
  2D: Stringed instrument plucked when lying flat (6)
• Quick crossword No 15,368 — 2019-08-08 23:00:37
  13A: Metal-stringed soundbox (6)