projector
gb/pɹəd͡ʒˈɛktɚ/ us/pɹəd͡ʒˈɛktɚ/
B1
English
~ 6100
Senses
0 senses
Noun
B1
entity
1
device that projects images
A machine that shines pictures or video onto a wall or screen so many people can see them.
Usage pattern:
to use a projector to show [images/video] on [a screen]
Common mistake:
Learners sometimes confuse "projector" with "protector" because they look similar in writing. They may also say "TV projector" when they mean a regular television; a projector needs a separate screen or wall to show the image.
Synonyms
video projector (More specific; clearly refers to a projector used for video, often from a computer or media player.)
|
beamer (Informal and mainly used in some European varieties of English; less common in general English.)
Antonyms
television (A self-contained display that shows images on its own screen instead of projecting them onto an external surface.)
Collocations
digital projector
|video projector
|overhead projector
|slide projector
|projector screen
|ceiling-mounted projector
Themes
technology
|education
|entertainment
|arts_entertainment
Examples
- The teacher connected her laptop to the projector to show the presentation.
- We set up a projector in the backyard to watch movies on a big sheet.
- Please turn off the projector when the meeting is over.
- The conference room has a ceiling-mounted projector and a large screen.
- The image from the projector was too dim because the bulb was old.
Learner examples
- The classroom has a new projector.
- He used a projector to show photos on the wall.
- They turned off the lights so the projector picture was clear.
- We watched a movie with a projector in the garden.
- Please plug the cable into the projector.
Noun
technical
C1
entity
2
idempotent mathematical projection operator
In higher mathematics, a special function or matrix that sends every point in a space onto part of that space and, if you apply it twice, nothing changes after the first time.
Usage pattern:
a projector maps [a vector] onto [a subspace]
Common mistake:
Learners may confuse the technical term "projector" with the everyday device that shows images. In mathematical texts, "projector" almost always refers to a projection operator, not a machine with a light.
Synonyms
projection operator (More explicit and common in technical writing; clearly labels the object as an operator performing a projection.)
Antonyms
identity operator (Leaves every element unchanged, instead of mapping elements onto a subspace as a projector does.)
Collocations
orthogonal projector
|projection projector
|rank-one projector
|matrix projector
|linear projector
Themes
mathematics
|science
|education
Examples
- The matrix P is an orthogonal projector onto the column space of A.
- Any projector in a finite-dimensional vector space can be represented by an idempotent matrix.
- We construct a projector that maps each state onto the invariant subspace.
- This operator acts as a projector onto the space of divergence-free fields.
- The eigenvalues of a nontrivial projector are always 0 or 1.
Learner examples
- In linear algebra, a projector sends a vector onto a smaller space.
- The teacher said that a projector has the property P times P equals P.
- This matrix is a projector onto the x-axis.
- A projector does not change a vector that is already in the subspace.
- We use a projector to separate the problem into two parts.
Noun
archaic
C2
entity
3
person who promotes schemes
An old word for a person who makes big plans or business schemes and tries to get people to support them.
Usage pattern:
a projector of [plans/schemes/reforms]
Synonyms
promoter (Modern word with a similar idea of supporting or organizing projects, but without the strong archaic or sometimes negative flavor.)
Antonyms
opponent (Someone who resists or argues against new schemes or projects, instead of proposing and pushing them forward.)
Collocations
bold projector
|political projector
|projector of schemes
|projector of reforms
Themes
history
|business
|finance
|work
Examples
- The pamphlet denounced him as a reckless projector of wild financial schemes.
- In the early eighteenth century, projectors sought charters for countless speculative companies.
- He was known in the city as a projector, forever chasing the next great enterprise.
- Such projectors promise wonders, yet rarely deliver any lasting benefit.
- The ministry dismissed him as a mere projector, not a serious statesman.
Learner examples
- In old books, a projector can mean a man with many plans.
- The king did not trust the projectors at his court.
- One projector wanted to build a new canal for trade.
- Writers in the past sometimes called crazy business people projectors.
- This meaning of projector is old and not used today.
Grammar
Dictionary form
projector
IPA
GB/pɹəd͡ʒˈɛktɚ/
US/pɹəd͡ʒˈɛktɚ/
Syllables & stress
pro - ject - or (3 syllables)
Stress on 2nd syllable (ject)
Word forms
Noun
- Base: projector
- Plural: projectors
Word family
Forms
projectors
noun
Core family
project
verb A2
projection
noun B2
Related words
projectionist
noun
Expressions
digital projector
1/dˈɪd͡ʒɪtəl pɹəd͡ʒˈɛktɚ/
fixed phrase
projector for digital images
A modern projector that shows pictures or video from a computer, phone, or other digital device.
Examples
- The conference room is equipped with a high-resolution digital projector.
- We connected the tablet to a digital projector for the presentation.
- They installed a new digital projector in the lecture hall.
film projector
1/fˈɪlm pɹəd͡ʒˈɛktɚ/
fixed phrase
projector for motion picture film
A projector that shows movies from reels of film onto a cinema screen.
Examples
- The old cinema still uses a traditional film projector.
- You can hear the sound of the film projector running during quiet scenes.
- They restored a 1950s film projector for the museum exhibit.
slide projector
1/slˈaɪd pɹəd͡ʒˈɛktɚ/
fixed phrase
projector for photo slides
A projector that shows small photo slides on a big screen or wall.
Examples
- My grandparents used a slide projector to show their holiday photos.
- The museum guide used a slide projector to present old images.
- He found an old slide projector and a box of slides in the attic.
video projector
1/vˈɪdioʊ pɹəd͡ʒˈɛktɚ/
fixed phrase
projector for video signals
A projector that shows video from devices like DVD players, game consoles, or computers on a large screen.
Examples
- They bought a video projector to create a home cinema.
- The video projector is connected to the game console for a bigger image.
- Make sure the video projector is set to the correct input source.
overhead projector
1/ˌoʊvɚhˈɛd pɹəd͡ʒˈɛktɚ/
fixed phrase
device that projects transparencies
A machine that shows words or pictures on a wall by shining light through a clear plastic sheet.
Examples
- Before digital projectors, teachers often used an overhead projector in class.
- The teacher used an overhead projector to show the diagram.
- She wrote on a transparent sheet and placed it on the overhead projector.
- Many schools have replaced overhead projectors with digital ones.
- The school finally replaced the old overhead projector with a modern system.