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').

Words like “turn on” are exactly the kind of vocabulary our English vocabulary size test measures — find out how many English words you know.

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