Refers to the period of life between childhood and adulthood, typically the teenage years into the early twenties. Often used in psychological, educational, or formal contexts.
Adolescence is a time of great change both physically and mentally.
彼は青年期に多くの本を読んだ。
He read many books during his youth.
Compound of 青年 (youth, young person) and 期 (period, stage). The word is a straightforward Sino-Japanese term for the developmental stage of adolescence.