ACER

Maple or sycamore, for example (4)

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

• Quick crossword No 16,401 — 2022-11-30 00:00:01
  19A: Tree with 'winged' seeds (4)
• Quick crossword No 16,054 — 2021-10-19 23:00:00
  21D: Maple or sycamore, for example (4)