godan verb (-tsu), intransitive verb
leave the nest; fledge
Literal use for birds or other animals leaving the nest after growing up.
ツバメのひなが巣立った。
The swallow chicks left the nest.
godan verb (-tsu), intransitive verb
leave home; become independent; go out into the world
Figurative use for a person becoming independent from parents, graduating, or starting adult life.
息子が大学を卒業して社会に巣立った。
My son graduated from university and went out into the world.
子供たちがみんな巣立って、家が静かになった。
All the children left home, and the house became quiet.