rejuvenile means an adult whose interests and activities are characteristic of those of children.
Etymology
From re- + juvenile. Compare rejuvenate.
noun
- An adult whose interests and activities are characteristic of those of children.“At $15 to $30 for each action figure, re-staffing the Cobra Command center (home to G.I. Joe's arch-nemesis, Cobra Commander) isn't cheap. So what's driving this rejuvenile movement? Marketing, mostly.”