off the hook

1 no longer in trouble or difficulty. informal

2 (of a telephone receiver) not on its rest, and so not receiving incoming calls.

☞ Hook in sense 1 is a long-standing (mid 15th-century) figurative use of the word to mean 'something by which a person is caught and trapped', as a fish hook catches a fish. Sense 2 is a fossilized expression from the late 19th century, the early years of telephony, when the receiver literally hung on a hook.