adverb (or adjective)
1. : in a state of freedom : without limits or restrictions as to movement
the more warlike tribes were still on the loose — Oliver La Farge
a dangerous animal … left on the loose — F.B.Gipson
2. : without moral restraint (as on behavior) ; especially : in a state characterized by unrestrained and usually dissolute behavior
the rowdy element, … drunken poachers and sailors on the loose — Saturday Review
she began shop-lifting and going on the loose again — Samuel Butler †1902