'Young' in the Bible

I made pools to give water for the woods with their young trees.

A young man who is poor and wise is better than a king who is old and foolish and will not be guided by the wisdom of others.

Because out of a prison the young man comes to be king, though by birth he was only a poor man in the kingdom.

I saw all the living under the sun round the young man who was to be ruler in place of the king.

Rejoice, O young man, in thy youth; and let thy heart cheer thee in the days of thy youth, and walk in the ways of thine heart, and in the sight of thine eyes: but know thou, that for all these things God will bring thee into judgment.