telescope

American  

[tel-uh-skohp] / ˈtɛl əˌskoʊp /

noun

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.

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adjective

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

verb (used with object)

telescoped, telescoping

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)

telescoped, telescoping

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

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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

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.

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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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Other Word Forms

• nontelescoping
  adjective

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.

Example Sentences

With a telescope you could not find a Hearts fan who does not believe now.

From BBC • May 4, 2026

There, Lowell convinced himself that alien-built canals crisscrossed the Martian surface, though anyone who has observed Mars with a similar telescope knows it’s hard to see much detail at all.

From The Wall Street Journal • Apr. 23, 2026

The telescope will send 11 terabytes of data a day down to Earth, said Mark Melton, a systems engineer at Goddard Space Flight Center.

From Barron's • Apr. 22, 2026

The event was so intense that no single telescope could capture the full picture.

From Science Daily • Mar. 30, 2026

How do we know that Galileo’s telescope was too good for naval and military use?

From "The Invention of Science" by David Wootton

Related Words

• abbreviate
• constrict
• cram
• restrict
• shorten
• shrink
• squeeze
• wrap