Collins COBUILD Advanced Learner's English Dictionary - grown-up

(grown-ups) Note: The spelling 'grownup' is also used. The syllable 'up' is not stressed when it is a noun. 1. A grown-up is an adult; used by or to children. Tell children to tell a grown-up if they’re being bullied. = adult N-COUNT 2. Someone who is grown-up is physically and mentally mature and no longer depends on their parents or another adult. I have grown-up children who’re doing well. ADJ 3. If you say that someone is grown-up, you mean that they behave in an adult way, often when they are in fact still a child. She’s very grown-up. ADJ: usu v-link ADJ 4. Grown-up things seem suitable for or typical of adults. (INFORMAL) Her songs tackle grown-up subjects... She talked in a grown-up manner. = adult ADJ