RAT

Despicable person (3)

Solution has appeared in 3 crosswords (3 across and 0 down):

• Quick crossword No 16,686 — 2023-10-27 23:00:00
  21A: Traitor (3)
• Quick crossword No 15,757 — 2020-11-06 00:00:43
  8A: Cheat (3)
• Quick crossword No 15,382 — 2019-08-25 23:00:23
  10A: Despicable person (3)