Adjective
grown-ass (not comparable)
(US, slang, vulgar) grown-up; adult; often used in reproach of an adult's immaturity, or, conversely, in assertion of maturity.
They call it a sport, but to me it looks like a bunch of grown-ass men running around like children.
Your mother is a grown-ass woman, and if she doesn't like you living your life for yourself rather than her, she can deal with it.
I am 35 years old, I am a grown-ass adult, and I am capable of choosing the right job myself, thank you very much.
What also stuck with me were all the threats Peter faced from grown-ass men and rabbits, who wanted to punish and hurt him (they were total sadists! Source: Internet
So, if you don't mind me asking, how does a grown-ass Black man end up being so damn stupid? Source: Internet