juvenility (n.)

Old English geong "youthful, young; recent, new, fresh," from Proto-Germanic *junga- (source also of Old Saxon and Old Frisian jung, Old Norse ungr, Middle Dutch jonc, Dutch jong, Old High German and German jung, Gothic juggs), from PIE *yuwn-ko-, suffixed form of root *yeu- "vital force, youthful vigor" (source also of Sanskrit yuvan- "young; young man;" Avestan yuuanem, yunam "youth," yoista- "youngest;" Latin juvenis "young," iunior "younger, more young;" Lithuanian jaunas, Old Church Slavonic junu, Russian junyj "young," Old Irish oac, Welsh ieuanc "young").

From c. 1830-1850, Young France, Young Italy, etc., were loosely applied to "republican agitators" in various monarchies; also, especially in Young England, Young America, used generally for "typical young person of the nation." For Young Turk, see Turk.