\ ˈbēm How to pronounce beam (audio) \

Definition of beam

 (Entry 1 of 2)

1a : a long piece of heavy often squared timber suitable for use in construction
b weaving : a wood or metal cylinder in a loom on which the warp (see warp entry 1 sense 1a) is wound
c : the part of a plow to which handles, standard, and coulter are attached
d : the bar of a balance from which scales hang
e : one of the principal horizontal supporting members (as of a building or ship) a steel beam supporting a floor also : boom, spar the beam of a crane
f nautical : the extreme width of a ship at the widest part
g engines : an oscillating lever on a central axis receiving motion at one end from an engine connecting rod and transmitting it at the other
2a : a ray or shaft of light beams from the searchlights
b : a collection of nearly parallel rays (such as X-rays) or a stream of particles (such as electrons)
c : a constant directional radio signal transmitted for the guidance of pilots also : the course indicated by a radio beam
3 : the main stem of a deer's antler
4 : the width of the buttocks … immensely broad in the beam— Ann Bridge
on the beam
1 : following a guiding beam
2 : proceeding or operating correctly


beamed; beaming; beams

Definition of beam (Entry 2 of 2)

transitive verb

1 : to emit in beams or as a beam (see beam entry 1 sense 2) The sun beamed its light through the window.
2 : to support with beams (see beam entry 1 sense 1) The house was beamed with heavy timbers.
3a : to transmit especially by satellite : broadcast … the 90-minute show was beamed to more than 200 countries and territories around the world.TV Guide
b : to transmit (data) electronically beaming images of the planet back to Earth The amount of data beamed over fiber-optic networks is rising exponentially every year, yet only 0.1% of fiber capacity is in use.— Leslie Cauley especially : to transmit (data) wirelessly Infrared connectivity enables users to work collaboratively on documents without having to log on to the network, and for quickly "beaming" data between different devices (for example, between two notebooks, or between a notebook and a printer, without a need for a cable). Newsweek
c : to direct to a particular audience a commercial beamed at middle-class voters

intransitive verb

1 : to send out rays of light Sunlight beamed through the window.
2 : to smile with joy The bride was beaming.

Keep scrolling for more

Synonyms for beam

Synonyms: Noun

Synonyms: Verb

Visit the Thesaurus for More 

Examples of beam in a Sentence

Noun a bright beam of light We saw the beams from their flashlights. the building's steel support beams Verb She beamed as she told us the good news. They stood beaming with satisfaction. “We're getting married!” he beamed. The sun beamed its light through the window. Pictures of the distant planet were beamed back to the Earth.
See More
Recent Examples on the Web: Noun An instrument bombards the particles with an infrared beam, exciting certain molecules in the sample, and analyzing the infrared signature reflected back at the detector. Matt Simon, Wired, "The Arctic Ocean Is Teeming With Microfibers From Clothes," 12 Jan. 2021 According to the Fire Department, the vehicle struck the carport, knocking down a support beam and causing the SUV to go over the edge. Kellie Hwang,, "Video: SUV crashes through San Leandro carport, dangles over embankment," 10 Jan. 2021 Unlike a space heater, which blows air across a hot electric coil to warm the air, a patio heater projects an infrared beam. Roy Berendsohn, Popular Mechanics, "The Best Patio Heaters To Beat The Winter Chill," 31 Dec. 2020 Hartford police received a 911 text on July 1 about a man sitting in a car with a firearm with a red beam on it, according to an arrest warrant. Rebecca Lurye,, "At vigil, loved ones mourn Shamar Ogman, Hartford man fatally shot by police," 30 Dec. 2020 This one from Perfectday is slim, reliable and rechargeable, and shines a small but intense beam on the page to ensure the reader sees the words but others close by aren’t disturbed by a glare. Michael Desjardin, USA TODAY, "35 perfect gift ideas for book lovers in 2020," 14 Dec. 2020 The project also required installation of a new steel beam in the kitchen ceiling to support the new structure. Kim Palmer, Star Tribune, "Ultra-modern addition updates a Craftsman-style house in St. Paul," 11 Dec. 2020 On the second floor, where a white scarf, called a khata, is draped over a beam as a sign of welcome, volunteers are making care packages for the sick, homebound and scared. New York Times, "The Epicenter," 3 Dec. 2020 One button operates the floodlight, and another operates a spot beam at high, medium, and low settings. Ben Romans, Field & Stream, "Great Survival Gift Ideas for 2020," 20 Nov. 2020 Recent Examples on the Web: Verb The company is also pressing ahead with another outrageously difficult project — a plan to flood Earth orbit with thousands of satellites that would beam Internet signals to ground stations, connecting rural areas to broadband. Washington Post, "2021 could be a huge year for space. Here’s what’s to come from NASA, Elon Musk, Richard Branson and Jeff Bezos.," 30 Dec. 2020 Founded in 2016, the company has launched two synthetic aperture radar (SAR) satellites that beam radio energy at the Earth from orbit, and decode its reflection back with a novel antenna design. Tim Fernholz, Quartz, "A startup is teaching the US military how to make space radar cheap," 17 Dec. 2020 The right kind of solar panels paired with storage could periodically beam power to specific places without losing notable energy. Caroline Delbert, Popular Mechanics, "The Air Force Is Building a Spacecraft That Will Beam Solar Power to Earth," 30 Dec. 2020 Some turned out to come from previously unknown astronomical sources such as pulsars, the rapidly rotating corpses of dead stars that beam radio waves into the cosmos. Nadia Drake, Science, "Alien hunters detect mysterious radio signal from nearby star," 18 Dec. 2020 While glass-panel costs have fallen considerably, sunlight is an intermittent and variable power supply thanks to nighttime, clouds, regional intensity and seasonality (unless an Elon Musk figure can beam solar power from space). William Levin, National Review, "We Have Time to Prevent Climate Change," 15 Dec. 2020 Installing reflective surfaces on rooftops or roads, which can help beam sunlight away, is another potential tool. Chelsea Harvey, Scientific American, "Climate Inequality Exists in U.S. Cities and Has Deep Racist Roots," 10 Dec. 2020 Satellite companies already use C-band airwaves to beam TV feeds and other content to receivers in the U.S. Drew Fitzgerald, WSJ, "Long-Awaited 5G Auction Expected to Stretch Carriers’ Balance Sheets," 8 Dec. 2020 Meanwhile, the probe will beam a radio signal toward the planet — and anyone else who might be listening — with an artistic and scientific message about life on Earth. Steven Litt, cleveland, "Oberlin artist Julia Christensen plans space art project for mission to planet 4.2 lightyears from Earth," 6 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'beam.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of beam


before the 12th century, in the meaning defined at sense 1a


15th century, in the meaning defined at transitive sense 1

History and Etymology for beam


Middle English beem, from Old English bēam tree, beam; akin to Old High German boum tree


Middle English bemen, verbal derivative of bem, beem beam entry 1

Keep scrolling for more

Learn More about beam

Time Traveler for beam

Time Traveler

The first known use of beam was before the 12th century

See more words from the same century

Statistics for beam

Last Updated

22 Jan 2021

Cite this Entry

“Beam.” Dictionary, Merriam-Webster, Accessed 23 Jan. 2021.

Keep scrolling for more

More Definitions for beam


How to pronounce beam (audio)

English Language Learners Definition of beam

 (Entry 1 of 2)

: a line of light coming from a source (such as the sun or a headlight)
: a line of energy, particles, etc., that cannot be seen
: a long and heavy piece of wood or metal that is used as a support in a building or ship



English Language Learners Definition of beam (Entry 2 of 2)

: to smile happily
: to say (something) while smiling happily
: to send out beams of light or energy


\ ˈbēm How to pronounce beam (audio) \

Kids Definition of beam

 (Entry 1 of 2)

1 : a long heavy piece of timber or metal used as a main horizontal support of a building or a ship a ceiling beam
2 : a ray of light
3 : a radio wave sent out from an airport to guide pilots


beamed; beaming

Kids Definition of beam (Entry 2 of 2)

1 : to send out beams of light Sunlight was beaming through the window.
2 : to smile with joy She beamed as she told us the good news.
3 : to aim a radio broadcast by use of a special antenna


\ ˈbēm How to pronounce beam (audio) \

Medical Definition of beam

1 : a ray or shaft of light
2 : a collection of nearly parallel rays (as X-rays) or a stream of particles (as electrons)

Keep scrolling for more

Comments on beam

What made you want to look up beam? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

 AlphaBear 2

Spell words. Make bears.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!