vacuum
vacuum — noun
1. a volume or container in which nearly all air and other gases have been taken ou
a volume or container in which nearly all air and other gases have been taken out, so that almost nothing is left inside.
The lab technician created a vacuum inside the glass tube before starting the test.
collocation: create a vacuum
Food stays fresh much longer inside a vacuum-sealed bag.
collocation: vacuum-sealed bag
Sound cannot travel through a vacuum because there are no particles to carry the waves.
The physicist used a vacuum pump to remove the air from the chamber.
- matter
the substance that is absent from a vacuum
- atmosphere
the air and gases that fill normal space
文法句型
a vacuum
under vacuum
in a vacuum
用法筆記
Countable when referring to a specific enclosed space (e.g., 'a vacuum chamber'). Uncountable when referring to the concept generally (e.g., 'sound does not travel in vacuum').
常見錯誤
2. a condition where an important or necessary element is missing, which creates a
a condition where an important or necessary element is missing, which creates a need or chance for it to be supplied.
After the prime minister resigned, a power vacuum led to months of political instability.
collocation: power vacuum
The company felt a creative vacuum after their lead designer moved to a rival firm.
collocation: creative vacuum
The sudden loss of funding left a vacuum that local donors struggled to fill.
A vacuum of reliable information allowed false rumours to spread quickly online.
文法句型
a vacuum of [something]
power vacuum
leadership vacuum
用法筆記
Typically used in fixed phrases like 'power vacuum', 'leadership vacuum', or 'a vacuum of + abstract noun'. Often refers to political or organisational contexts.
常見錯誤
3. a state of being completely cut off from surrounding people, events, or influenc
a state of being completely cut off from surrounding people, events, or influences, especially when that separation causes problems.
The committee cannot make this decision in a vacuum — they must listen to what the community thinks.
idiom: in a vacuum (isolated from context)
No business operates in a vacuum; every company is affected by the broader economy.
Scientists warned that studying climate patterns in a vacuum would ignore the social factors driving change.
Raising a child in a vacuum, without friends or family nearby, can be very difficult.
- context
the surrounding circumstances that should inform decisions
- connection
the links to other people and events that are absent in a vacuum
文法句型
in a vacuum
用法筆記
Almost always appears in the fixed phrase 'in a vacuum' as an adverbial modifier. The phrase is nearly always used in negative or cautionary contexts ('can't do X in a vacuum').
常見錯誤
4. an electrical household appliance that cleans floors, carpets, and upholstery by
an electrical household appliance that cleans floors, carpets, and upholstery by sucking up dust and dirt.
Lien plugged in the vacuum and cleaned the living room after the party.
collocation: plug in the vacuum
This vacuum has a special filter that traps pet hair and dust mites.
Christopher took the vacuum upstairs to clean the bedrooms before the guests arrived.
The vacuum needs a new bag — the old one is completely full of dust.
Isabela borrowed my vacuum to clean her car after the camping trip.
- vacuum cleaner
the full, formal name for the appliance
- hoover
UK informal / trademark genericisation; used as both noun and verb
文法句型
the vacuum
a vacuum
use the vacuum
用法筆記
In British English, 'hoover' (from the brand name) is commonly used as a synonym for both the noun and verb. 'Vacuum cleaner' is the full, formal term.
常見錯誤
vacuum — verb
1. to rid a surface such as a floor, carpet, or piece of furniture of dust and smal
to rid a surface such as a floor, carpet, or piece of furniture of dust and small particles by means of a suction-cleaning appliance.
Adisa vacuumed the living room before the dinner guests arrived.
transitive: vacuum + room
Have you vacuumed under the sofa cushions? There are biscuit crumbs everywhere.
Wren vacuums the office every evening after the last employee leaves.
Zayd spent the whole Saturday morning vacuuming the car seats and floor mats.
The robot vacuum cleans the kitchen floor while the family is at work.
- mess up
to make something dirty, the opposite of cleaning it
文法句型
vacuum + [room/area]
vacuum [something]
vacuum (no object)
用法筆記
Can be used transitively (vacuum + surface/room) or intransitively ('I need to vacuum'). In UK English, 'hoover' is a very common alternative.
常見錯誤
vacuum — adjective
1. containing or having a partial vacuum, meaning the air pressure inside is lower
containing or having a partial vacuum, meaning the air pressure inside is lower than the surrounding atmospheric pressure.
Coffee stays hot for hours inside a good vacuum flask.
collocation: vacuum flask
Vacuum packaging keeps food fresh by removing the air from the bag.
collocation: vacuum packaging
The lab uses a vacuum chamber to test how electronic parts behave at low pressure.
A vacuum-sealed container kept the coffee beans fresh for over a year.
- pressurised
having higher rather than lower air pressure inside
用法筆記
Almost always used attributively before a noun (vacuum flask, vacuum chamber, vacuum packaging). Not used predicatively ('the flask is vacuum').
2. relating to or used in devices and systems that operate by creating or using a p
relating to or used in devices and systems that operate by creating or using a partial vacuum.
Old radio sets contained vacuum tubes that amplified the electrical signal.
collocation: vacuum tube
A vacuum pump removes air from a sealed container to create low-pressure conditions.
collocation: vacuum pump
The engineer checked the vacuum gauge to make sure the pressure had dropped enough.
The factory installed a new vacuum system to handle the packaging process.
- suction-based
broader term that includes but is not limited to vacuum technology
用法筆記
Attributive only — appears before technical nouns like 'tube', 'pump', 'gauge', 'valve'. Do not use predicatively.