All their children have 'flown the coop'. [=have moved away from home]
Her books are filled with abstract ideas and 'high-flown' language.
In the morning the suspect had 'flown the coop'.
(..) aaam rreeeuddd wwwAwinnddd, wwwAwhhhicchhh rmmaaamrrinneeeurrssss caaamlheeeuddd ''aaam sssmeeeaaam oofff dddaaamrrkkknneeesssmssss.'' And red sand from this wind... hss flown ss far ss the south cosst of England apparently producing... showers so dense that they were mistaken for blood. (..)1996 The English Patient