A contestant on the Channel 4 gameshow Countdown is being praised online for winning a round with the word “hentai” – much to the amusement of viewers.

Marwan Riach unearthed the six-letter word – which refers to a genre of sexually explicit or pornographic anime or manga – from an jumble of nine letters.

In the episode which aired on Monday afternoon, Riach and his opponent were presented with the nine-letter mix “TINEYATPH”.

His opponent, Tom Silverlock, could only find the five-letter word “patty”.

With 30 seconds to think, Riach sheepishly admitted he found six. “Uh, hentai?” he offered.

Susie Dent, Dictionary Corner’s resident etymologist, responded: “Hentai is brilliant.”

Dent defined it as “a subgenre of a Japanese anime or manga”, but did not mention its pornographic nature. The guest Suzi Perry suggested a better word, for seven letters, was “patient”.

Hentai is defined by the Oxford Dictionary as “a subgenre of the Japanese genres of manga and anime, characterised by overtly sexualised characters and sexually explicit images and plots”.

It originates from the Japanese words hentai seiyoku sha, which means someone who is perverted, and came into its current use in the 1990s.

Screenshots and clips of the episode were shared widely online.

Riach ended the round on 50 points, trailing Silverlock’s 60, and went on to lose the episode 84 points to 64. But on Twitter, where screenshots and clips of his choice were shared widely, he was embraced.

“Big props to the guy on # Countdown who just (very nervously!) threw out ‘Hentai’ as a winning word,” said one viewer.

Another viewer said he had been unlucky to lose the game in the final round.

Riach said: “My mind just went blank as I knew if I’d won that game, I (probably) would have beaten him. Was good fun though and would definitely recommend applying if it’s the sort of thing you like.”

In 2014, the long-running gameshow faced a similar conundrum when one of the Hairy Bikers chefs offered the word “todgers”. In 2010, the letters U, D, F, C, K and E all appeared, but no contestant picked the obvious expletive.