on the loose

English edit

(idiomatic) Not incarcerated or in captivity; not under control.
There were reports of a giraffe that escaped from the zoo, on the loose in New York.
(slang, archaic) Out on a spree, or in search of adventure.
(slang, archaic) Earning a living by prostitution.
- 1868, The Indian Medical Gazette, volume 3, page 21:
  Many doctors practising in large cities dwell on the difficulty of checking clandestine prostitution, which is unfortunately on the increase in all crowded centres, where numbers of women are on the loose, over whom the police have little or no hold.

not in captivity

(earning a living by prostitution): John Camden Hotten (1873) The Slang Dictionary