bigkid
nounUK /ˈbɪɡ.kɪd/
US /ˈbɪɡ.kɪd/
A bigkid is a child who is older and acts more grown-up.
My little brother wants to be a bigkid like me.
OTHER MEANINGS
2. A child who is tall for their age.
She's a bigkid, already taller than her teacher.
3. A child who helps take care of younger kids.
The bigkid showed the little ones how to tie their shoes.
4. A playful name for someone acting childish but trying to seem mature.
Stop acting like a bigkid and share your toys.