The part of life that succeeds to childhood; the period of existence preceding maturity or age; the whole early part of life, from childhood, or, sometimes, from infancy, to manhood.

the time of life between childhood and maturity

To dream of your own youth denotes continuing ease and comfort.

The United Nations defines a youth as a person between the ages of 15 and 24. Generally, it is the time in a person's life between childhood and adulthood. Source: United Nations

Youth (Russian: Юность [Yunost']; 1856) is the third novel in Leo Tolstoy's autobiographical trilogy, following Childhood and Boyhood.

Youth (or Youth: Scenes from Provincial Life II) (2002) is a semi-fictionalised autobiographical book by J. M. Coetzee, recounting his struggles in 1960s London after fleeing the political unrest of Cape Town. After graduating in mathematics and English, he moves in the hope of finding inspiration of becoming a poet and finding the woman of his dreams.

Youth is a science fiction short story by Isaac Asimov. It first appeared in the May 1952 issue of Space Science Fiction and was reprinted in the 1955 collection The Martian Way and Other Stories. "Youth" is one of the rare Asimov stories with alien characters.