speed

speed — 名詞

1. a measure of how far something travels in a fixed amount of time, usually given

1.名詞A2
釋義

速率

物體在單位時間內移動的快慢程度

a measure of how far something travels in a fixed amount of time, usually given in units such as kilometres per hour or metres per second.

例句

The train was moving at a speed of 220 kilometres per hour as it passed through the countryside.

火車以每小時 220 公里的速率駛過鄉間，穿越田野。

at a speed of [number] + distance unit

Strong winds can reduce the speed of a cyclist by nearly half on a flat road.

強風可能會使自行車騎士在平路上的速率減少將近一半。

speed of [something]

同義詞
  • velocity

    technical term used in physics; includes direction of movement

  • pace

    used especially for walking, running, or rate of progress

  • rate

    more general; can apply to speed, price, or frequency of events

文法句型

at a speed of [number]

at high/low/full speed

speed of [something]

用法筆記

Speed differs from velocity because velocity also tells you the direction of movement. In everyday English, speed is far more common than velocity.

常見錯誤

❌The car was going with a speed of 100 km/h.
✅The car was going at a speed of 100 km/h.
💡use the preposition 'at', not 'with'.
❌The speed of the car was fast.
✅The car was moving at high speed.
💡speed itself is a measurement, not something that is fast or slow.

2. the characteristic of acting or moving swiftly, without taking a long time.

2.名詞A2
釋義

快速

動作或移動非常快的特性

the characteristic of acting or moving swiftly, without taking a long time.

例句

Abigail was surprised by the speed with which the waiter brought their meals to the table.

Abigail 很驚訝服務生以如此快的速度把餐點送到他們的桌上。

the speed with which [clause]

The cheetah's speed makes it the fastest land animal on the planet.

獵豹的快速使牠成為地球上跑得最快的陸地動物。

同義詞
  • swiftness

    more formal and literary; often used for movement through air or water

  • rapidity

    formal; used for both physical movement and rate of change

  • quickness

    everyday word; can apply to both movement and mental reaction

反義詞

文法句型

with speed

at speed

用法筆記

This sense describes the quality of being fast rather than a measured rate. Compare with noun sense 1: 'the speed of the car was 80 km/h' (measured) vs 'he drove with great speed' (quality of fastness).

常見錯誤

❌She ran with a speed.
✅She ran with speed.' or 'She ran at great speed.
💡this sense is uncountable; do not use 'a speed'.

3. a measurement that tells you how quickly a task or process is completed.

3.名詞B1
釋義

速度

某件事情發生的快慢程度

a measurement that tells you how quickly a task or process is completed.

例句

The speed of the economic recovery surprised most financial analysts last year.

經濟復甦的速度讓去年多數的金融分析師感到意外。

speed of [process]

Owen improved the typing speed of his students by running daily timed exercises.

Owen 透過每天定時練習來提高學生的打字速度。

同義詞
  • pace

    the rate at which something progresses, not necessarily measured in units

  • tempo

    used especially for music, work, or life rhythm

文法句型

at speed

speed of [action/process]

用法筆記

Like sense 1, this can be measured, but it applies to how quickly a process completes rather than how far something travels. Common in business and technology contexts: 'processing speed', 'download speed', 'speed of service'.

4. the constant rate at which a wave, for instance a light wave or a sound wave, pa

4.名詞B2
釋義

波速

光或聲音等波動在介質中傳播的固定速率

the constant rate at which a wave, for instance a light wave or a sound wave, passes through a medium.

例句

The speed of light in a vacuum is about 300,000 kilometres per second.

光在真空中的波速約為每秒三十萬公里。

speed of light / sound (fixed scientific constant)

Sound travels at different speeds through water than it does through air.

聲音在水中和空氣中傳播的波速並不相同。

文法句型

speed of light / sound / wave

用法筆記

In physics, this sense is almost always preceded by a prepositional phrase naming the wave type: 'the speed of light', 'the speed of sound'. These are well-known constant values used in calculations.

常見錯誤

❌Light speed is very fast.
✅The speed of light is very high.
💡the expression is 'the speed of light' or 'lightspeed', not 'light speed' as two words without the article.

5. a particular gear in a vehicle or bicycle that allows the wheels to turn at a di

5.名詞B1
釋義

檔位

車輛或自行車上改變轉速的齒輪設定

a particular gear in a vehicle or bicycle that allows the wheels to turn at a different rate compared to the engine or pedals.

例句

Kabir shifted into a lower speed before the bicycle began to climb the steep hill.

Kabir 在自行車開始爬上陡峭的山坡前換到較低的檔位。

shift into / change speed

Antonia bought a twenty-one-speed mountain bike for riding on rough forest trails.

Antonia 買了一輛二十一檔的登山車，用來騎在崎嶇的森林小徑上。

[number]-speed [bicycle / vehicle]

同義詞
  • gear

    more common in modern car contexts; 'speed' is more traditional for bicycles

文法句型

[number]-speed [vehicle]

first/second/third… speed

change speed

用法筆記

Common in compound nouns: 'three-speed bicycle', 'five-speed gearbox'. When counting gears, 'speeds' is the plural form. In modern cars, 'gear' is more common than 'speed' for this sense.

6. a number printed on photographic film that tells you how strongly the film react

6.名詞C1
釋義

感光度

底片或感光元件對光線的敏感程度數值

a number printed on photographic film that tells you how strongly the film reacts to light; a higher number means the film needs less light to create a picture.

例句

Tamar chose a film with a speed of 400 for the indoor birthday party with dim lighting.

Tamar 選了一卷感光度 400 的底片，要在燈光昏暗的室內生日派對上拍照。

film speed of [number] (ISO/ASA rating)

High-speed film allows photographers to take clear pictures in low light without a flash.

高感光度底片讓攝影師可以在光線不足的環境下不使用閃光燈就拍出清晰的照片。

high-speed / low-speed film

同義詞
  • ISO

    the international standard notation for film speed; often used as a direct substitute

  • ASA

    older American standard for the same measurement; still seen on vintage equipment

文法句型

film speed of [number]

high-speed film

用法筆記

Expressed as an ISO number (e.g., ISO 200, ISO 400). Higher numbers = more sensitive = faster speed. This sense is primarily used for traditional film cameras, not digital, though 'ISO speed' is still used in digital photography.

7. the period during which a camera's shutter remains open so that light can hit th

7.名詞C1
釋義

快門速度

相機快門打開讓光線進入的時間長短

the period during which a camera's shutter remains open so that light can hit the film or digital sensor inside the camera body.

例句

A fast shutter speed of 1/1000 second can freeze the motion of a bird in flight.

千分之一秒的快門速度可以將飛翔中的鳥兒瞬間定格。

shutter speed of [time fraction]

With a slow shutter speed, Anjali captured the blur of car lights on the highway.

Anjali 用慢速快門捕捉到高速公路上車燈的光影模糊效果。

fast / slow shutter speed

文法句型

shutter speed of [fraction]

fast/slow shutter speed

用法筆記

Usually appears as 'shutter speed' rather than just 'speed' alone. Measured in fractions of a second (1/125, 1/250) or in whole seconds for long exposures.

8. an illegal drug, especially amphetamine or methamphetamine, that makes the user

8.名詞C2
釋義

安非他命

一種能讓使用者感到亢奮的非法毒品

an illegal drug, especially amphetamine or methamphetamine, that makes the user feel more awake and energetic.

例句

The documentary warned young people about the dangers of using speed and other street drugs.

這部紀錄片警告年輕人使用安非他命等街頭毒品的危險。

Police found a small quantity of speed hidden in the glove compartment of the stolen car.

警方在被偷車輛的置物箱裡發現了一小批安非他命。

collocation: quantity of speed / using speed

同義詞
  • amphetamine

    the medical name for the drug; neutral register

  • meth

    short for methamphetamine; also informal but more specific

  • crystal

    slang for crystal meth, a more potent form

用法筆記

Highly informal slang. Not used in formal or academic writing. The word appears without an article: 'He was arrested for selling speed', not 'a speed'. Use with caution in learner contexts.

常見錯誤

❌He took a speed.
✅He took speed.
💡uncountable; no article needed.

speed — 動詞