1. a person who is fully developed and mature; an adult
Usage: often written as two words (grown-up) or hyphenated

1. characteristic of or suitable for an adult; mature
Usage: often written as two words (grown-up) or hyphenated

Examples

• My older sister is a grownup now and lives in her own apartment.
• The children were excited to sit at the grownup table during dinner.
• He tried to act grownup, but his nervousness gave him away.
• Grownups have more responsibilities than children do.
• That movie has some grownup themes that might not be suitable for young viewers.
• She made a grownup decision to pursue her education instead of taking the easy path.