Robin van Persie becomes latest Manchester United star to leave mark on Channel 4 programme Countdown. Here's a conundrum for you. What's Manchester United striker Robin van Persie doing on cult television show Countdown? Following on from Ryan Giggs' appearance on the Channel 4 programme earlier this year, Van Persie became the latest Old Trafford star to leave his mark on the popular afternoon show. Viewers were left perplexed and bemused in equal measure when the nine-letter conundrum 'vanpersio' appeared on their screens during Wednesday's programme. And so were the two contestants, who both failed to solve the puzzler during the 30-second time limit. For those of you equally challenged,Sportsmailcan reveal the answer: pervasion. The Oxford Dictionary tells us it means 'the process of permeating or infusing something with a substance'. It's unclear whether Riley, a lifelong Man United supporter, had a hand in the conundrum. The 27-year-old, currently showing off her best moves on BBC One's Strictly Come Dancing, was surprised earlier this year when Giggs presented her with a United shirt to mark her 1,000th appearance on the show. 'I had no inkling that I had just filmed my 1,000th episode when (presenter) Nick (Hewer) announced it on the show, and I was touched that the Countdown team had surprised me with the news,' Riley said. 'As Nick continued, I thought they might have got me a bunch of flowers. But I nearly fell through the floor when Ryan Giggs suddenly appeared with some. 'As a lifelong red, I’ve watched Giggsy rack up 1,000-plus appearances since I was five, so there couldn’t have been a more special way to celebrate mine.'