Learner's definition of YOUTH
1 : the time of life when someone is young : the time when a young person has not yet become an adult
He spent his youth in the Midwest.
He got into a lot of trouble in his youth.
a generation trying to recapture lost youth
(Brit) a youth club [=a club that provides various activities for young people]
2 [noncount] : the time when something is new and not yet established 3 [count] : a teenage boy or young man 4 the youth : young people 5 [noncount] : the quality or state of being young