beam

beam — noun

1. a narrow band of light coming from the sun, a lamp, or another bright thing

1.名詞B2
釋義

a narrow band of light coming from the sun, a lamp, or another bright thing

例句

A beam of sunlight fell across the kitchen floor at breakfast.

beam of + light source

One beam from the lighthouse cut through the fog before dawn.

beam from + object

同義詞
  • ray

    very close in meaning, and often slightly more scientific or literary

  • shaft

    suggests a stronger visible column, often through an opening

  • streak

    often thinner or more temporary, and not always from one clear source

文法句型

a beam of light

a beam from something

用法筆記

Usually appears in patterns such as beam of light or beam from a lamp, torch, or window. Distinguish from sense 2, which is mainly used for scientific radiation or particle flow rather than ordinary visible light.

常見錯誤

❌A beam light came through the door.
✅A beam of light came through the door.
💡beam usually takes of light when you name the light itself.

2. a flow of energy or tiny particles moving together in one direction

2.名詞C2
釋義

a flow of energy or tiny particles moving together in one direction

例句

The doctor aimed the X-ray beam at Noah's broken wrist.

X-ray beam

Inside the lab, a narrow electron beam hit the metal plate.

electron beam

同義詞
  • ray

    common with radiation, especially X-rays and similar energy

  • stream

    fits moving particles especially well, but is broader and less technical

文法句型

an X-ray beam

an electron beam

用法筆記

Often follows a type word such as X-ray, laser, or electron. Distinguish from sense 1: this sense is common in science and medicine, even when nothing can be seen by the eye.

常見錯誤

❌The lab used a light beam of electrons.
✅The lab used an electron beam.
💡in scientific use, the type normally comes before beam.

3. a long heavy bar of wood, steel, or concrete that supports weight in a roof, flo

3.名詞B2
釋義

a long heavy bar of wood, steel, or concrete that supports weight in a roof, floor, or bridge

例句

Workers lifted the steel beam into place above the new shop.

steel beam

One cracked beam made the old barn roof unsafe.

roof beam

同義詞
  • girder

    more technical and especially common for large steel supports

  • support beam

    a fuller phrase with nearly the same meaning

  • joist

    usually a smaller supporting piece in floors or ceilings

文法句型

a steel beam

a roof beam

用法筆記

Most often modified by material or position, as in steel beam, roof beam, or ceiling beam. Distinguish from sense 4, which is the sports apparatus and event.

常見錯誤

❌The builders put a beam support under the roof.
✅The builders put a support beam under the roof.
💡support normally comes before beam in this building sense.

4. the narrow wooden bar used for balance routines in women's gymnastics, or the ev

4.名詞C1
釋義

the narrow wooden bar used for balance routines in women's gymnastics, or the event performed on it

例句

Sofia kept her arms wide as she stepped onto the beam.

step onto the beam

The judge took points off when Mia slipped on the beam.

on the beam

同義詞
  • balance beam

    the full name of the apparatus

  • beam event

    refers especially to the competition rather than the wooden bar itself

文法句型

on the beam

step onto the beam

用法筆記

Often used with on in sports reports and coaching talk, as in win on beam or fall on the beam. Distinguish from sense 3, which refers to a building support rather than a gymnastics event or apparatus.

常見錯誤

❌She practiced on the balance wood.
✅She practiced on the beam.
💡the apparatus is called a beam or balance beam, not balance wood.

beam — verb