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telescope

American  
[tel-uh-skohp] / ˈtɛl əˌskoʊp /

noun

  • telescopes
    plural
  1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms refracting telescope, or refractor consists essentially of an objective lens set into one end of a tube and an adjustable eyepiece or combination of lenses set into the other end of a tube that slides into the first and through which the enlarged object is viewed directly; the other form reflecting telescope, or reflector has a concave mirror that gathers light from the object and focuses it into an adjustable eyepiece or combination of lenses through which the reflection of the object is enlarged and viewed.

  2. Astronomy. Telescope, the constellation Telescopium.


adjective

  1. consisting of parts that fit and slide one within another.

verb (used with object)

  • telescopes,
    present (3rd person singular)
  • telescoped,
    past participle,  past
  • telescoping
    present participle
  1. to force together, one into another, or force into something else, in the manner of the sliding tubes of a jointed telescope.

  2. to shorten or condense; compress.

    to telescope the events of five hundred years into one history lecture.

verb (used without object)

  • telescopes,
    present (3rd person singular)
  • telescoped,
    past participle,  past
  • telescoping
    present participle
  1. to slide together, or into something else, in the manner of the tubes of a jointed telescope.

  2. to be driven one into another, as railroad cars in a collision.

  3. to be or become shortened or condensed.

telescope British  
/ ˈtɛlɪˌskəʊp /

noun

  1. an optical instrument for making distant objects appear larger and brighter by use of a combination of lenses (refracting telescope) or lenses and curved mirrors (reflecting telescope) See also terrestrial telescope astronomical telescope Cassegrain telescope Galilean telescope Newtonian telescope

  2. any instrument, such as a radio telescope, for collecting, focusing, and detecting electromagnetic radiation from space

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. to crush together or be crushed together, as in a collision

    the front of the car was telescoped by the impact

  2. to fit together like a set of cylinders that slide into one another, thus allowing extension and shortening

  3. to make or become smaller or shorter

    the novel was telescoped into a short play

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
telescope Scientific  
/ tĕl′ĭ-skōp′ /
  1. An arrangement of lenses, mirrors, or both that collects visible light, allowing direct observation or photographic recording of distant objects.

  2. ◆ A refracting telescope uses lenses to focus light to produce a magnified image. Compound lenses are used to avoid distortions such as spherical and chromatic aberrations.

  3. ◆ A reflecting telescope uses mirrors to view celestial objects at high levels of magnification. Most large optical telescopes are reflecting telescopes because very large mirrors, which are necessary to maximize the amount of light received by the telescope, are easier to build than very large lenses.

  4. Any of various devices, such as a radio telescope, used to detect and observe distant objects by collecting radiation other than visible light.


telescope Cultural  
  1. A device used by astronomers to magnify images or collect more light from distant objects by gathering and concentrating radiation. The most familiar kind of telescope is the optical telescope, which collects radiation in the form of visible light. It may work by reflection, with a bowl-shaped mirror at its base, or by refraction, with a system of lens es. Other kinds of telescopes collect other kinds of radiation; there are radio telescopes (which collect radio waves), x-ray telescopes, and infrared telescopes. Radio and optical telescopes may be situated on the Earth, since the Earth's atmosphere allows light and radio waves through but absorbs radiation from several other regions of the electromagnetic spectrum. X-ray telescopes are placed in space.


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Etymology

Origin of telescope

First recorded in 1610–20; tele- 1 + -scope; replacing telescopium (from New Latin ) and telescopio (from Italian ); see -ium

Explanation

A telescope is an instrument that is used to view distant objects. If you want to look at the planets, you can use a telescope. The higher the magnification on the telescope, the better your view will be. Galileo is often credited with the invention of the telescope, but this is incorrect. Although he didn't invent it, he did improve it — a lot. He didn't name the telescope either; Greek mathematician Giovanni Demisiani did, in 1611. Telescope is from the Greek roots tele."far," and skopos, "seeing;" so it literally describes what the instrument does. As a verb, telescope means "to become smaller through one part sliding into another," the way a portable collapsing telescope does.

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Vocabulary lists containing telescope

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Operating with a telescope at Palomar Observatory in California, ZTF repeatedly photographs large sections of the night sky.

From Science Daily ● Oct. 10, 2026

The 82-year-old is the brains behind the IceCube Neutrino Observatory, a telescope embedded in a cubic kilometer of Antarctic ice that detects neutrinos -- particles with almost no mass that seldom interact with other matter.

From Barron's ● Oct. 6, 2026

These women - all in their late 20s - grew up watching these stars, but it was only a few years ago that they learnt to study them through a telescope.

From BBC ● Sep. 26, 2026

The ability to anticipate these eruptions may become particularly useful for major future observatories, including the Square Kilometre Array radio telescope project, which is expected to begin collecting scientific data in 2028.

From Science Daily ● Sep. 21, 2026

Duane was fairly certain it was the sunlight hitting C.C.’s metal telescope atop the slanted deck.

From "The Very, Very Far North" by Dan Bar-el

These rare signals carry clues to where the neutrinos came from and the extreme conditions that produced them — allowing scientists to investigate places that ordinary telescopes cannot easily see.

From BBC ● Oct. 6, 2026

"I was traveling home by train," recalls Passaleva, "and all of a sudden I was rushing against time to commandeer one of the largest telescopes in the world from my laptop."

From Science Daily ● Sep. 30, 2026

The boundary of the observable universe is not merely the farthest distance our telescopes can currently reach.

From Science Daily ● Sep. 28, 2026

Over 15 days, they learnt to identify stars, planets and constellations, navigate the night sky, operate telescopes and photograph the Milky Way on their phones.

From BBC ● Sep. 26, 2026

Within a day or two he had left; Galileo was thus in Rome as the Jesuit astronomers turned their telescopes on Venus and watched it move towards a half-circle.

From "The Invention of Science" by David Wootton

But this time around, in Burkina Faso, the timetable has telescoped.

From BBC ● Jan. 26, 2022

An entire lifetime, in all its rushing and monotonous variety, is telescoped into a breathless 15 minutes in Samuel Beckett’s primal cry of a monologue, delivered by a disembodied mouth.

From New York Times ● Oct. 7, 2020

There were two wheels at one end and a handle that telescoped out from the base at the other.

From Washington Post ● Nov. 18, 2018

At the Sirius Town Hall, the old “Mike and the Mad Dog” jingle plays, and fans in throwback Mets jerseys gather, and time has been telescoped.

From Los Angeles Times ● Jul. 11, 2017

The entire fifty-foot pedestal telescoped downward into a spiral staircase.

From "Blood of Olympus" by Rick Riordan

For the encore, they cleared the perimeter of the stadium floor and drove around on giant, telescoping platforms, trailed by inflatable characters, like they were in a Macy's Day parade.

From BBC ● Sep. 25, 2025

Then we step forward — you can think of telescoping in on finer and finer timescales — we get from the billion year timescale to the hundreds of millions year timescale.

From Salon ● Sep. 29, 2023

Whether it’s Tetrised inside a delivery truck, cradling a cappuccino or telescoping over a tampon, cardboard is a paradox.

From Los Angeles Times ● Aug. 3, 2023

This trait formed what Ella and I came to call a telescoping process, with parts stretching back across time, marking the discontinuity between past and present, and then collapsing it.

From Scientific American ● Jun. 14, 2023

I went into uniform at the time when our enemies began to recede so fast that there had to be a hurried telescoping of military training plans.

From "A Separate Peace" by John Knowles

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