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turn (up)on someone or something
to attack or oppose someone or something, especially the person or group in charge. (Upon is formal and less commonly used than on.) I never thought that my own dog would turn on me! The treasurer turned on the entire board of directors.
turn someone on
to excite or interest someone. Fast music with a good beat turns me on. That stuff doesn't turn on anyone.
turn something on
to switch on something to make it run. I turned the microwave oven on and cooked dinner. I turned on the lights when the sun went down.
turn on someone
to attack someone. I thought the strange dog was friendly, but suddenly it turned on me and bit me. Bob knows a lot about lions, and he says that no matter how well they are trained, there is always the danger that they'll turn on you.
1. Lit.[for something] to switch on and start running. The lights turned on right at dusk. At what time do the street lights turn on?
2. Fig. to become interested or excited. He turns on when he sees the mountains. Ann will turn on if she hears this song.
1. Cause to begin the operation, flow, or activity of, as in Turn on the lights, please, or Don't turn on the sprinkler yet. [First half of 1800s]
2. Begin to display, employ, or exude, as in He turned on the charm. [Late 1800s]
3. Also, get high or on . Take or cause to take a mind-altering drug, as in The boys were excited about turning on, or They tried to get her high, or I told them I wouldn't get on tonight. [Slang; mid-1900s]
4. Be or cause to become excited or interested, as in His mother was the first to turn him on to classical music. [c. 1900]
5. Be or become sexually aroused, as in He blushed when she asked him what turned him on. [Second half of 1900s]
6. Also, turn upon. Depend on, relate to, as in The entire plot turns on mistaken identity. This usage, first recorded in 1661, uses turn in the sense of "revolve on an axis or hinge."
7. Also, turn upon. Attack, become hostile toward, as in Although normally friendly, the dog suddenly turned on everyone who came to the door. Also see turn against.
1. To suddenly aim or focus something on someone or something: She turned the camera on the speaker. He turned the gun on himself.
2. To attack someone or something suddenly and violently with no apparent motive: The lion turned on the animal trainer.
3. To become disloyal toward someone that one was once loyal to: After years as an assistant, I turned on my boss and told the authorities about his tax evasion.
4. To depend on someone or something for success or failure: The campaign turns on attracting swing voters.
5. To start the operation, activity, or flow of something by or as if by turning a switch: Turn on the light bulb. Turn the generator on.
6. To begin instantly to display, employ, or exude some affectation: She turned on the charm. He turns a fake accent on when he doesn't want to be recognized.
7. Slang To take a mind-altering drug, especially for the first time: They turned on and passed out at the party.
8. Slang turn on to To cause to become interested, pleasurably excited, or stimulated by something: My aunt turned me on to jazz.
9. Slang turn on to To be interested, pleasurably excited, or stimulated by something: She turned on to surfing this summer.
10. Vulgar Slang To excite someone sexually.
1. in. to become interested or excited. She turned on when she heard her name called.
2. in. to take a drug. (Drugs.) He will turn on with anybody at the drop of a hat.
3. n. someone or something that excites someone. (Usually turn-on.) David can be a real turn-on when he’s in a good mood.