bulb

bulb — noun

1. the small glass unit in an electric light that glows when power is on.

1.名詞B1
釋義

the small glass unit in an electric light that glows when power is on.

例句

Diego changed the bathroom bulb before the guests arrived.

collocation: change a bulb

A dead bulb left the hall dark all night.

a bulb goes dead

同義詞
  • light bulb

    the full everyday phrase; clearer when context is missing

  • lamp

    often means the whole light fixture, not only the glass part

  • LED

    often refers to a modern bulb type or its lighting technology

文法句型

change a bulb

a bulb goes dead

screw in a bulb

用法筆記

Usually names the replaceable shining part, not the whole lamp or light fitting. Common verbs are change, replace, fit, and screw in.

常見錯誤

❌The bulb on my desk is broken, so I need a new bulb and stand.
✅The lamp on my desk is broken, so I need a new lamp.
💡'bulb' is only the part that gives light; the whole object is usually a 'lamp'.
❌The lamp is dead, just buy a new lamp.
✅The bulb is dead, just buy a new bulb.
💡When only the shining part has failed, use 'bulb', not 'lamp'.

2. the thick round part under the ground that stores food and later sends up a new

2.名詞B2
釋義

the thick round part under the ground that stores food and later sends up a new plant, as in tulips or onions.

例句

Priya planted tulip bulbs along the front path before winter came.

collocation: plant bulbs

Each bulb sent up green leaves after the first warm week.

intransitive growth: a bulb sent up leaves

同義詞
  • corm

    a similar plant part, but botanically different and less common in everyday speech

  • tuber

    another food-storing plant part, usually not layered like a bulb

  • root

    a broader everyday word; not every root is a bulb

文法句型

plant bulbs

a bulb grows

lift bulbs from the ground

用法筆記

Often used for garden plants that are planted one season and flower in the next. Distinguish from an ordinary root: a bulb is the round food-storing part that can grow a whole new plant.

常見錯誤

❌The tulip root was dry, so we planted it in a pot.
✅The tulip bulb was dry, so we planted it in a pot.
💡Tulips grow from bulbs, not from ordinary roots.

3. the little glass section at the bottom of a thermometer that holds the liquid be

3.名詞C1
釋義

the little glass section at the bottom of a thermometer that holds the liquid before it moves up the tube.

例句

The nurse shook the thermometer until the liquid fell back into the bulb.

thermometer liquid in the bulb

On the lab table, the bulb held red liquid below the scale.

bulb held liquid

同義詞
  • bulb end

    a descriptive phrase rather than a fixed technical term

  • reservoir

    more technical; focuses on the part that holds the liquid

  • chamber

    a general word for an enclosed space, not specific to thermometers

文法句型

the bulb of a thermometer

liquid in the bulb

crack the bulb

用法筆記

Usually appears with thermometer or with a phrase naming its position, such as at the bottom of the tube. Distinguish from sense 4: this bulb is a hard glass part that holds liquid, not a soft part you press.

常見錯誤

❌The number is inside the bulb.
✅The liquid is inside the bulb, and the number is on the scale.
💡In a thermometer, the bulb holds the liquid; the numbers are printed outside.

4. the soft round end on some tubes or droppers that you press to push air or liqui

4.名詞C1
釋義

the soft round end on some tubes or droppers that you press to push air or liquid through.

例句

Hana squeezed the rubber bulb to fill the dropper with medicine.

collocation: squeeze the rubber bulb

A blue bulb at the tube's end sent air into the fish tank.

bulb at the end of a tube

同義詞

文法句型

squeeze the bulb

press the bulb

bulb at the end of a tube

用法筆記

Usually modified by rubber, soft, or suction, and used with verbs like squeeze or press. Distinguish from sense 3: this part is flexible and is used by hand to move air or liquid.

常見錯誤

❌Push the tube to take up the medicine.
✅Squeeze the bulb to draw up the medicine.
💡The bulb is the soft part you press; the tube is the narrow part that carries the liquid.