left the nest

Verb

leave the nest (third-person singular simple present leaves the nest, present participle leaving the nest, simple past and past participle left the nest)

1. (idiomatic) To leave home; to stop living with one's parents.
   • At about the time that the last child is leaving the nest, elderly parents move to a point of needing assistance in their lives.1987, Sue Vineyard, How to Take Care of You . . . So You Can Take Care of Others, →ISBN, page 31

   Synonyms:

   fly the nest

2. (idiomatic) To become independent; to begin to act without supervision or in ways that are not prescribed.
   • He taught, seasoned, encouraged, and broadened all of us while we were his students, and he supported us greatly after we had left the nest.2000, G. Srinivasan, From White Dwarfs to Black Holes: The Legacy of S. Chandrasekhar, →ISBN
3. Used other than figuratively or idiomatically: see leave, nest.
   • Checking nests keeps the adult birds away from the nest, exposing the eggs and chicks to cold or heat, and can cause large chicks to leave the nest prematurely.2006, Peter Ryan, Sasol Birdwatching in Southern Africa, →ISBN, page 84