light bulb

IPA/ˈlaɪt bʌlb/
IPA/ˈlaɪt bʌlb/

light bulb — noun

1. a rounded glass or plastic object that screws into a lamp or ceiling socket and

1.名詞A2
釋義

a rounded glass or plastic object that screws into a lamp or ceiling socket and glows to give out light when connected to electricity.

例句

Mira replaced the broken light bulb in her bedside lamp with a new one.

The light bulb above the kitchen table needs to be changed soon.

同義詞
  • bulb

    shorter, everyday equivalent

  • lamp

    the whole device that holds the bulb, not the bulb itself

用法筆記

Countable noun. Often used with a specifying phrase ("light bulb in...") or a modifier ("energy-saving light bulb", "LED light bulb").

常見錯誤

❌Could you turn on the light bulb?
✅Could you turn on the lamp / the light?
💡'light bulb' is the bulb itself, not the whole lamp.
❌The light bulb is too dark.
✅The light bulb is not bright enough.
💡'dark' describes a lack of light, not the bulb's capacity.

2. a moment when someone suddenly understands something or has a clever idea that t

2.名詞B2
釋義

a moment when someone suddenly understands something or has a clever idea that they did not have before — as if a mental light has been switched on.

例句

A light bulb went off in Yasmin's head when she finally understood the maths problem.

idiom: a light bulb goes off in someone's head

Brian had a light bulb moment during the meeting and solved the budget problem.

collocation: light bulb moment

同義詞

文法句型

a light bulb goes off / appears (in / above someone's head)

a light bulb moment

用法筆記

Almost always occurs in fixed expressions such as "a light bulb goes off" or "a light bulb moment." The physical bulb is not actually involved — the image is of a light switching on inside the mind. Distinguish from sense 1 (the physical object).

常見錯誤

❌I had a light bulb moment, so I bought one at the store.
✅I had a light bulb moment in class when I understood the formula.
💡the figurative sense describes a sudden realization, not an actual bulb.