lightbulb

Everyday

1. A lightbulb is a glass or plastic bulb that gives out light when electricity goes through it. tree →
2. (informal) A «lightbulb moment» is a sudden moment when you understand something or have a great idea. tree →

In the lessons

Science: electric circuits, energy saving (LED bulbs use less energy than old filament bulbs); history: Thomas Edison and Joseph Swan. Cartoons: a lightbulb over someone's head means an idea. Safety: let bulbs cool before touching and switch off before changing.

Examples

• The lightbulb in my bedroom has gone. tree →
• LED lightbulbs save energy. tree →
• Switch off before you change a lightbulb. tree →
• Edison and Swan both worked on the lightbulb. tree →
• I had a lightbulb moment and solved the puzzle. tree →
• In the circuit, the lightbulb lit up when we closed the switch. tree →

Note

Also «light bulb» (two words). Plural: lightbulbs. Myth: Edison did not invent the first bulb; many people worked on it.