n. An adult who enjoys activities and items normally associated with children.
Other Forms
But in his new book "Rejuvenile: Kickball, Cartoons, Cupcakes, and the Reinvention of the American Grown-up" (Crown, $17.95), author Christopher Noxon has finally come up with a definition broad enough to get everyone on the same playground.

Meet the "rejuveniles."

According to Noxon, 36, rejuveniles are people who have "tastes or mind-sets that are traditionally associated with people younger than themselves."

The idea for the book came from the author's own rejuvenile epiphany, when he realized he had a wife and kids, a mini-van and a receding hairline but still didn't feel like a grown-up.

"Most of my days were spent playing Legos with my kids or watching old "H.R. Pufnstuf" videos and having a good time in a way that I knew my own parents found pretty ridiculous," he said.
—Rod O'Connor, “Adulthood: Are we there yet?,” Chicago Tribune, August 06, 2006
Mom is at a pajama party. Dad is organizing a rock, paper, scissors tournament. Will they ever grow up and start behaving like adults or are they part of a new breed of "rejuveniles?"

Playful adults — those who refuse to give up fun just because they have a mortgage — are redefining what it means to be a grown-up in the 21st century.
—Jill Serjeant, “'Rejuveniles' reinvent meaning of adulthood,” Reuters News, July 25, 2006
2001 (earliest)
The $35 Independence Bath comes with a Philly soft pretzel and choice of local beer. Aren't baths supposed to whisk you away from daily life, rather than plunking you right in it? The Gentlemen's Bath ($35) includes cognac and a cigar. Mr. Bubble Bath ($25) comes with hot chocolate, cookies and rubber duck. I am looking for something that would rejuvenate, not rejuvenile. So, I opt for the Stress Relief bath.
—Karen Heller, “Awash in luxury,” The Philadelphia Inquirer, January 16, 2001