I'm afraid it's not a real word, and the inability to find it any dictionary will confirm that.
Richard Ayoade used the 9 letters on the countdown board in a humorous manner as, had it been a real word, it would have won.
The episode in question was not a "real" episode of Countdown - I believe it was an episode of The IT Crowd.
Answer from Ste on Stack ExchangeI'm afraid it's not a real word, and the inability to find it any dictionary will confirm that.
Richard Ayoade used the 9 letters on the countdown board in a humorous manner as, had it been a real word, it would have won.
The episode in question was not a "real" episode of Countdown - I believe it was an episode of The IT Crowd.
No, It hasn't been considered a real word so far.
Although you may find the word and its definition in some sites, it can't be found in any mainstream dictionary: Merriam-Webster, Oxford English Dictionary, etc. The moment you find "tnetennba" in such sources, you can affirm it is a real word.
Definition of "tnetennba". Meaning 1: A word whose function is purely to attract traffic to a website. Meaning 2: Someone who looks up words which have been artificially created for the purpose of fiction or comedy.