turn loose

to turn loose (third-person singular simple present turns loose, present participle turning loose, simple past and past participle turned loose)

1. (transitive, idiomatic) To release or let go; to permit (someone or something) to roam freely or to act freely.

   Don't turn the dog loose in the yard before you check whether the gate is closed.

   He's so creative, and I'd love to turn him loose in my garden sometime and see what he dreams up.

• let loose, set free, set loose