fly the nest
To move out of one's parents' house for the first time. I'm so nervous to fly the nest and start college this fall because I've never lived on my own before. I can't believe my little girl is getting ready to fly the nest. I'm so proud and so sad all at once!
fly the nest
or leave the nest
When children fly the nest or leave the nest, they leave their parents' home to live on their own. When their children had flown the nest, he and his wife moved to a cottage in Dorset. One day the children are going to leave the nest and have their own lives. Compare with fly the coop.
fly the nest
(of a young person) leave their parent's home to set up home elsewhere. informal The image here is of a young bird's departure from its nest on becoming able to fly. Compare with empty nester (at empty).
ˌfly the ˈnest
1 (of a young bird) become able to fly and leave its nest
2 (informal) (of somebody’s child) leave home and live somewhere else: Their children have all flown the nest now.