lightbulb

/ˈlaɪt ˌbʌlb/
noun
  1. A glass device that produces light when electricity passes through it, used in lamps and fixtures.
    • She screwed the lightbulb into the lamp and turned on the switch.
    • LED lightbulbs use less energy and last longer than traditional ones.
    • I need to replace the lightbulb in the kitchen ceiling fixture.
  2. A sudden idea or moment of inspiration.
    • When she saw the diagram, a lightbulb went off in her head.
    • The inventor's lightbulb idea came to him while he was taking a shower.
    • He had a lightbulb moment and solved the math problem instantly.
Synonyms