Mary O’Brien estimates she has compiled about 12,000 of the crosswords, and her 15th book will appear in August to mark the anniversary The popular Irish Times Simplex crossword made its debut on May 21st, 1951, following demands from some readers who were stumped by Crosaire, the cryptic crossword Thu May 21 2026 - 06:00 • 4 MIN READClue: What has been turning up in the strangest places for 75 years and been found on the altar, in orchestral pits, on labour wards and in the Dáil chamber? (3, 7 letters) Solution: The Simplex.The popular Irish Times crossword made its debut on May 21st, 1951, following demands from some readers who were stumped by Crosaire, the cryptic crossword. It has been simultaneously thrilling and annoying readers ever since.The first ever Simplex clue was: Do this to the child and spoil him (6). All self-respecting cruciverbalists will instantly know that the correct answer is “pamper”. The compiler of the Simplex crossword Mary O’Brien would never use the mock-Latin word cruciverbalist to describe what she does. “I usually say I’m a crossword compiler, and sometimes a setter, but never a cruciverbalist.”She became guardian of the Simplex in 1986, taking over from the original Simplex setter Basil Peterson. At first she shared the task with Gerry Colgan, continuing alone after his death. She estimates that she has compiled about 12,000 crosswords and produced 14 books. Her 15th will appear in August to mark the 75th anniversary of the puzzle.The Simplex originally appeared three days a week, but readers clamoured for more, so it began appearing every day. When O’Brien took on the task of compiling it, she would spend a week making one crossword. Now it only takes a couple of hours. “Simplex was originally compiled by hand, so I could easily back myself into a corner with no possibility of connecting words,” she says. “In that event, I might have had to start all over again. Now, thankfully, I use a [computer] programme called Crossword Compiler which tells me when a word has or has not interconnected words... I fill in all the grids first, then all the clues.“ .” Her trusty Chambers dictionary is always on hand, but just as people get lost scrolling through social media, she can spend hours getting lost in obscure dictionary entries.She still remembers the thrill of expanding her vocabulary when she first attempted the Simplex many years ago. “I used to love when I learned a new word, but now people get very cross if I put in a word that they don’t know,” she says. That wasn’t a complaint years ago when many more unfamiliar words were used. “And then other people get annoyed when I use anagrams.”Every so often the Simplex causes a stir on the Letters Page of this newspaper, when readers complain that it’s more complex than simplex. Recent letter-writers have taken umbrage at the use of words such as otiose, neophyte and epithet, but she remembers an older online controversy with a shudder. The crossword answer was “epidural” but an error crept into her clue when she described the exact injection point. “And on Twitter this man who was an adjunct professor of anaesthesiology and an anaesthetist put up a picture of the crossword,” she recalls. “By the end of the day, that had gone all over the world. It moved from anaesthetists to the general medical area. There were people commenting from Australia on it. And of course he was absolutely right to point it out. I apologised of course, but the apology did not get as much attention.”But any negative feedback is greatly outweighed by the positive, and readers regularly say it is the highlight of their day. Before the puzzles went online, she was told that expectant parents were saving up the crosswords for use as a distraction during labour. A letter-writer to this newspaper told how, as a musician in the Gaiety Theatre pit orchestra, he would prop the crossword among the music on his stand for entertainment when he was not playing.[ Simplex repeats this obscure word every 40 years. What does it mean?Opens in new window ]“Years ago, before we went digital, a gang in UCD would photocopy them and they would have a race, and whoever finished first would get their coffee paid for,” she recalls. “And I was at a funeral once when one of the gifts brought up was the Simplex crossword. The priest said all this woman wanted was a glass of Merlot and her crossword.”Younger readers often prefer to do their crossword online these days, but “I know some of the older ones prefer the paper page”, she says, “as I do myself.”Is it too easy now for people to google the answers? “I’m sure there are some who do google, but what would be the point? It defeats the purpose.”Some acquaintances who bump into her in the morning worry she will divulge the answers before they get a chance to complete the Simplex, but there is no risk of that, as she is notoriously discreet. She even refuses to be drawn on the famous people who tell her they are fans. “A well-known Irish poet told me her father had difficulty understanding her occupation as a full-time poet, but when he saw her name in a Simplex clue with ‘poet’ as the solution, he finally accepted it as legitimate,” she says. “I was delighted.”[ On the wrong impression as to just how complex Simplex isOpens in new window ]Mary O’Brien is 82 now but has no plans to lay down her pencil. “The great thing is that crossword compilers don’t retire,” she says. “You can do it forever and you can do it sitting down.”Is it the best job in the world for someone who loves words (3)? Solution: Yes.IN THIS SECTION