grow up

Short definition: The phrase grow up means to develop from a child into an adult, or to behave in a more mature and responsible way, depending on context.

Looking for a clear and natural explanation of the phrasal verb grow up? This phrase is extremely common in English and is often connected to childhood, maturity, and personal development. It can describe becoming an adult physically, maturing emotionally, or even being told to behave more responsibly. Sometimes it’s neutral, and sometimes it can sound critical depending on tone. Below are detailed meanings with realistic examples so you can clearly understand how grow up works in daily English.

Forms: grow up, grows up, grew up, grown up, growing up
Related: grown-up n./adj., maturity n., adulthood n., mature v.
Syllable: grow-up

1. (Verb) To develop from a child into an adult.

   To grow up most commonly means to become an adult physically and socially. It describes the natural process of aging from childhood through teenage years into adulthood. This meaning focuses on development over time.

   She grew up in a small town surrounded by mountains.
   When I grow up, I want to become a doctor.
   They have known each other since they were children growing up together.

   Synonyms: mature physically, become an adult, reach adulthood, develop fully, come of age, age naturally, advance in years, pass through childhood, mature over time, reach maturity, develop into adulthood, grow older
   Antonyms: stay young, remain childish, regress, act immature, refuse to mature, stay dependent, remain infantile, behave childishly, avoid adulthood, remain underdeveloped, stay immature, cling to childhood

2. (Verb) To become more emotionally mature or responsible.

   Grow up can also refer to emotional maturity. It means developing responsibility, better judgment, and the ability to handle situations calmly. This meaning is often used when encouraging someone to behave more seriously or thoughtfully.

   He needs to grow up and take responsibility for his actions.
   She really grew up after facing those challenges.
   At some point, we all have to grow up and accept reality.

   Synonyms: mature emotionally, become responsible, develop character, act your age, gain wisdom, become sensible, show maturity, take responsibility, become independent, become serious, behave responsibly, develop perspective
   Antonyms: act childish, behave immaturely, be irresponsible, throw tantrums, avoid responsibility, stay reckless, remain naive, refuse to learn, act foolishly, stay immature, behave irresponsibly, regress emotionally

3. (Verb) Used informally as a criticism meaning “stop being childish.”

   In informal speech, telling someone to grow up can sound critical. It usually means you think the person is acting immaturely or overreacting. The tone can be playful or serious depending on context.

   “Oh, grow up! It was just a joke.”
   He told his friend to grow up and stop complaining about small problems.
   Sometimes siblings tell each other to grow up during arguments.

   Synonyms: act mature, be sensible, behave properly, stop acting childish, get serious, act responsibly, be realistic, calm down, take it seriously, show maturity, stop whining, act your age
   Antonyms: stay childish, continue whining, overreact, throw a fit, behave immaturely, stay dramatic, remain silly, refuse to mature, stay irresponsible, act foolishly, exaggerate, keep complaining

4. (Verb) To gradually develop or expand over time.

   Grow up can also describe something gradually increasing or developing, such as a business, idea, or organization. This meaning focuses on expansion rather than age.

   The small startup has grown up into a successful international company.
   The town has really grown up over the past decade.
   His passion project slowly grew up into a full-time career.

   Synonyms: expand, develop, evolve, mature over time, progress, advance, flourish, increase in size, become established, strengthen, build up, transform gradually
   Antonyms: shrink, decline, regress, weaken, collapse, deteriorate, remain small, stagnate, fall apart, diminish, fail to develop, stay undeveloped