turn on

What it means

To activate a device, appliance, or light by pressing a switch, button, or tap. Informally, it can also mean to excite someone or to suddenly attack someone (often as 'turn on someone').

Examples

• Could you turn on the lights? It's getting dark.
• She turned the TV on to watch the news.
• Don't forget to turn on the dishwasher before bed.
• The dog suddenly turned on its owner — it was scary.

Where it comes from

Separable: 'turn on the radio' or 'turn the radio on', and pronouns must go in the middle ('turn it on'). The opposite is 'turn off'. The phrase comes from literally turning a knob or tap to start a flow, dating back to before electric switches existed.

Related phrasal verbs