Longman Dictionary of Contemporary English - youth

~ n plural youths 1 the period of time when someone is young, especially the period between being a child and being fully grown  (Youth is a time when many people rebel against their parents. | in sb's youth (=when they were young))  (In his youth, Jimmy was an idealist and a rebel.) 2 a word meaning boy or young man, especially a teenager, used especially when you disapprove of them  (gangs of youths hanging about on street corners)  (- see child) 3 (also + plural v BrE) young people considered as a group  (the courage of youth | the youth of)  (The youth of the country are being ignored by politicians.) 4 the quality or state of being young  (a product that claims to restore youth and vitality to your skin)