a mature, fully grown person; adult.
Other definitions for grown-up (2 of 2)
having reached the age of maturity.
characteristic of or suitable for adults: grown-up behavior; grown-up fiction.
- grown-upness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use grownup in a sentence
Two years into the job, he was approached about creating a burger with a distinctly adult taste to shift the perception of McDonald’s from a place for families to a place for anyone, childless grownups included.The Arch Deluxe Was a Hell of a Burger. It Was Also McDonald’s Most Expensive Flop. | Jeremy Glass | July 23, 2021 | Eater
These getaway spots offer perks for the grownups, like mountain bike trails, surf breaks, and rooftop bars, as well as the drive-in movie theaters, hot-springs-fed pools, and skate parks that will keep the kids happy.
This is a strategy game for the whole family, easy enough for the middle school set, but challenging enough for the grownups with just a touch of divine intervention to keep everyone on their toes.37 Gifts to Buy This Mother's Day for Every Type of Mom in Your Life | Melissa Locker | May 3, 2021 | Time
For years, the classy, grownup A Beautiful Mind–type movies have generally flowed into theaters beginning in early fall.The Vibe Will Be Different at This Year’s Oscars—and That’s a Good Thing | Stephanie Zacharek | April 21, 2021 | Time
Robinhood’s awkward adolescence hasn’t kept it from raising very grownup sums.Robinhood’s next adventure: Stealing market share from the rich | Jeff | December 3, 2020 | Fortune
I was happy Dad had let me be a grownup with him for a little while.
Star Trek always seemed like a slightly more grownup, intellectual, and philosophical version of the genre.Simon Pegg on His First ‘Star Trek’ Memories, Playing Scotty, and More | Simon Pegg | May 13, 2013 | THE DAILY BEAST
If you think it is wrong, then act like a grownup and wait until you can buy it legally.Why Are Cable Companies Forcing People to Turn to Piracy? | Megan McArdle | November 28, 2012 | THE DAILY BEAST
And with a fine dose of ribbon embroidery and a bit of sparkle, grunge was dressed up enough for a grownup.
They were not ostentatious as much as they were happy—in a grownup, made-peace-with-it-all way.
Lucy Jane Bull and her sisters were quite old enough to understand a good deal of grownup conversation when they overheard it.In the Yule-Log Glow, Book II | Various
Onward and still onward to a glorious end, left entirely to myself and entrusted with an important task like a grownup person!The Bride of the Nile, Complete | Georg Ebers
Now, you and I, grownup, walk along the sidewalks of San Francisco and all we see under our calloused old feet is a sidewalk.Vignettes Of San Francisco | Almira Bailey
Rosa Stevenson's grownup sister is going away next month to be a missionary!A Missionary Twig | Emma L. Burnett
Father, mother, two grownup sons, and one or two daughters--evidently by a former marriage.The Sign Of The Red Cross | Evelyn Everett-Green
British Dictionary definitions for grown-up
having reached maturity; adult
suitable for or characteristic of an adult
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012