Youth
Young Man
noun
Someone who is blue in their years. This makes sense when you know that Asian babies are often born with blue butts, which you can associate with being young. So, Blue = Young (not only in this word, but in others as well). Someone who is blue in their years is a youth.
せいねん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
とてもさわやかな青年でした。
He was a very invigorating young man.
その青年は、ぼう走ぞくの一いんです。
That young man is a member of a motorcycle gang.
どうして日本の青年は、下心があっていやらしい笑みを浮かべていることを隠そうとするのか？
Why do youths in Japan try to hide their nasty smiles when they’re up to something?