grown-up child
nounUK /ˌɡrəʊnʌp ˈtʃaɪld/
US /ˌɡroʊnʌp ˈtʃaɪld/
A grown-up child is a person who is no longer a kid.
Their grown-up child visits them every weekend.
RELATED WORDS
OTHER MEANINGS
2. An adult who still acts like a child.
He still throws tantrums like a grown-up child.
3. A child who seems older than their age.
She is a grown-up child who helps with the bills.
4. A person treated as a child by their parents even as an adult.
At family dinners, he is still the grown-up child at the kids' table.