turn off verb 11turn-off noun 2forms 4 verb11 •To power down, to switch off, to put out of operation, to deactivate (an appliance, light, mechanism, functionality etc.).Turn off the machine and unplug it when you leave.In some people, this gene has been turned off. •To deactivate a heat source cooking a particular item.You can turn off the green beans now. •To become deactivated; to become powered down.My computer turned off! •To rotate a tap or valve so as to interrupt the outflow of liquid or gas.Remember to turn the tap off once you've finished so you don't waste water. •To bore, repulse, disgust, or discourage (someone).That book's plot was so predictable, it turned me off.Cigarette smoking really turns me off. •To leave a road; to exit a highway or other main road.You'll need to turn off before we get to the county line.Turn off at the next exit so we can have lunch. •(old-fashioned) To avert; to stop (something)."Pardon my clumsiness," he said to the lady. "I am, unfortunately, quite blind. But," he added, with a smile, to turn off the mishap, "even a blind man must have a house." — 1914 •To raise, unblocking the way and signaling that a train may proceed. •(no longer used) To dismiss; to fire.The butler turned off that foolish maid. •(no longer used) To turn out; to produce.According to D. A. Wells, one boy and a machine can turn off 9,000 pair of sleeve buttons in a day. — 1895 •(slang, no longer used) To execute by hanging.The thief was turned off by the hangman. turn-off noun2 •(informal) Something that repulses, disgusts, or discourages, especially sexually.I like the people at my job, but the 60-hour work weeks are a big turn-off.Braces on a pretty girl actually aren't a turn-off for me. •A road where one turns off, such as a motorway exit. formsturned off · turning off · turns off · turn-offs