IRREVERSIBLE

Not able to be annulled (12)

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

• Quick crossword No 15,711 — 2020-09-13 23:00:12
  17A: Permanent (12)
• Quick crossword No 15,423 — 2019-10-11 23:00:05
  17A: Not able to be annulled (12)