1.
When you turn on a piece of equipment or a supply of something, you cause heat, sound, or water to be produced by adjusting the controls.
I want to turn on the television...
She asked them why they hadn't turned the lights on.
= switch on
? turn off
PHRASAL VERB: V P n (not pron), V n P
2.
If someone or something turns you on, they attract you and make you feel sexually excited. (INFORMAL)
The body that turns men on doesn't have to be perfect.
? turn off
PHRASAL VERB: V n P
3.
If you say that someone turns on a particular way of behaving, you mean that they suddenly start behaving in that way, and you are often also suggesting that this is insincere. (INFORMAL)
He could also turn on the style when the occasion demanded.
PHRASAL VERB: V P n (not pron), also V n P
4.
If someone turns on you, they attack you or speak angrily to you.
Demonstrators turned on police, overturning vehicles and setting fire to them...
PHRASAL VERB: V P n
5.
If something turns on a particular thing, its success or truth depends on that thing.
The plot turns on whether Ilsa will choose her lover or her husband.
= hinge on
PHRASAL VERB: V P n