Crossword Genius

Follower of four or six but not three or five (4)

Ross

I believe the answer is:

teen

(Other definitions for teen that I've seen before include "Juvenile" , "Youngster of a certain age" , "Adolescent, then adult-to-be" , "Youth" , "Young person" .)

I've seen this clue in The New York Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.