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1. verb To become older and more mature; to progress toward adulthood. When I grow up, I want to be an astronaut Growing up with three older brothers probably did a lot to shape my personality.
2. verb To arise or emerge. Protests have grown up all across the nation in response to that incident.
3. expression An imperative to be more mature, typically directed at someone exhibiting what the speaker considers to be extremely immature behavior. Oh, grow up and take some responsibility for your actions. Ugh, you guys are so immature! Grow up!
to become mature; to become adult. All the children have grown up and the parents are left with a lot of debts.
1. Become an adult, as in Sam wants to be a policeman when he grows up. [First half of 1500s]
2. Come into existence, arise, as in Similar social problems grew up in all the big cities. [Late 1500s]
3. Become mature or sensible, as in It's time you grew up and faced the facts. This usage may also be in the form of an imperative (as in Don't bite your nails-grow up!) [Mid-1900s]
To become an adult: I want to be a teacher when I grow up.