young adultnoun
uk/ˌjʌŋ ˈæd.ʌlt//ˌjʌŋ ˈæd.ʌlt//ˌjʌŋ əˈdʌlt//ˌjʌŋ əˈdʌlt/[ C ] a person who is in his or her late teenage years or early twenties:
Now that my kids are young adults, I'm grateful we're still close.
casual wear for teens and young adults
[ U ] abbreviation YA books written for readers in their late teenage years or early twenties:
The site lists publications in such categories as young adult, science fiction, fantasy, and horror.
young adult fiction
the young adult section of the bookstore