Definition: To behave like a grown-up even though your use of the word "adulty" would indicate otherwise.

Sample usage: "Do I really want to buy decorative towels for the bathroom? That's so adulty."

Popularity: You won't catch anyone over 30 using the word. At least, we hope not. It suggests both a longing for maturity and a genial sneer toward being "responsible," and lets everyone know you're still exciting and quirky. Technically an adult, but not, you know, an adult adult. It'll be very popular.

JAMES LILEKS

Heard a new word or phrase you want us to dissect? Let us know at word@startribune.com. Check out previous entries at startribune.com/word.