SUIT

It constitutes one quarter of a deck (4)

Solution has appeared in 2 crosswords (2 across and 0 down):

• Quick crossword No 16,399 — 2022-11-28 00:00:09
  17A: Diamonds, say (4)
• Quick crossword No 15,672 — 2020-07-29 23:00:02
  1A: It constitutes one quarter of a deck (4)