From fly, to flee or run away, + coop, an enclosure for birds.
fly the coop (third-person singular simple present flies the coop, present participle flying the coop, simple past flew the coop, past participle flown the coop)
- (idiomatic) To depart hastily or unannounced; to escape or flee.
- 1910, William MacLeod Raine, A Texas Ranger, ch. 3:
- Not liking the accommodations, I took the first chance and flew the coop.
- (of a bird) To escape from a pen or similar enclosure.
- 1961 Jan. 6, "Assisi Revisited," Time:
- Explained a Curtiz assistant: "We had three ravens in Assisi; one died of cold, and another flew the coop."
- Usually used in the simple past form.