Urologists? Norway? These were just two of the unlikely words Jason Segel had to drop into the conversation during a hilarious game of Word Sneak on Wednesday, July 29's Tonight Show Starring Jimmy Fallon.

And despite some obvious reservations about taking part in one of Fallon's now infamous celebrity talk show games, Segel proved himself to be a pretty nimble wordsmith as he swerved conversations round to help him complete his challenge.

"Are you in for this?" Fallon asked his show guest, 35, as he explained the rules of the game.

"Of course," he replied quickly. "I don't have a choice," added with a grin.

"No you don't," admitted Fallon. "That's why I asked you on camera!"

Things started off relatively easily — with Segel dropping the word "mongoose" into the chat while revealing he's way more of a winter guy than a summer guy.

Helping Fallon segue into a conversation about squat thrusts, the Sex Tape actor then declared himself to be fluent in Norwegian, despite having reservations about the sensibilities of the country's talkshows!

But it was the six-foot-four star's attempts to drop Gene Shalit's name into conversation (and he got there via talk of onions and pants) that really reduced everyone, including the audience, into hysterics!

Watch the whole hilarious video in the clip above.

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