A beam is a long board that's used to hold up a roof or doorway. The beams in your kitchen ceiling help support the upstairs floor just above it.

In construction, beams are made of wood or metal and are used to frame a building and provide structure. In gymnastics, a beam is used for balancing and doing tricks on. If someone comments that you're getting "broad in the beam," they're disparaging the width of your body, especially your hips. In Old English, a beam first meant a tree, and later a rafter or a ship's timber.

Primary Meanings of beam

long thick piece of wood or metal or concrete, etc., used in construction
a column of light (as from a beacon)
emit light; be bright, as of the sun or a light
have a complexion with a strong bright color, such as red or pink
the broad side of a ship
Full Definitions of beam

n long thick piece of wood or metal or concrete, etc., used in construction

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box beam, box girder
a beam built up from boards; has a hollow rectangular cross section
projecting horizontal beam fixed at one end only
a beam made usually of steel; a main support in a structure
a framing member crossing and supporting the ends of joists, studs, or rafters so as to transfer their weight to parallel joists, studs, or rafters
header, lintel
horizontal beam used as a finishing piece over a door or window
beam used to support a floor or ceiling
one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability
a longitudinal beam connected to the keel of ship to strengthen it
balk, baulk, rafter
one of several parallel sloping beams that support a roof
rider plate
a horizontal beam (or plate) connected to the top of a ship's vertical keel or to the keelson
ridge, ridgepole, rooftree
a beam laid along the edge where two sloping sides of a roof meet at the top; provides an attachment for the upper ends of rafters
shore, shoring
a beam or timber that is propped against a structure to provide support
tie, tie beam
a horizontal beam used to prevent two other structural members from spreading apart or separating
a beam made of wood
crossbeam, crosspiece, trave, traverse
a horizontal beam that extends across something
bilge keel
either of two lengthwise fins attached along the outside of a ship's bilge; reduces rolling
a timber member grooved to take a sliding panel
floor joist
joist that supports a floor
girder having a cross section resembling the letter `I'
(nautical) the principal upright timber at the stern of a vessel
a long horizontal timber to connect uprights
trimmer, trimmer joist
joist that receives the end of a header in floor or roof framing in order to leave an opening for a staircase or chimney etc.
a timber measuring (slightly under) 2 inches by 4 inches in cross section
Type of:
a separate part of a whole
structural member
support that is a constituent part of any structure or building

n a gymnastic apparatus used by women gymnasts

balance beam
Type of:
exerciser, gymnastic apparatus
sports equipment used in gymnastic exercises

n a column of light (as from a beacon)

beam of light, irradiation, light beam, ray, ray of light, shaft, shaft of light
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heat ray
a ray that produces a thermal effect
high beam
the beam of a car's headlights that provides distant illumination
moon ray, moon-ray, moonbeam
a ray of moonlight
sunbeam, sunray
a ray of sunlight
laser beam
a beam of light generated by a laser
low beam
the beam of a car's headlights that provides illumination for a short distance
infrared ray
a ray of infrared radiation; produces a thermal effect (as from an infrared lamp)
Type of:
light, visible light, visible radiation
(physics) electromagnetic radiation that can produce a visual sensation

n a group of nearly parallel lines of electromagnetic radiation

electron beam, ray
cathode ray
a beam of electrons emitted by the cathode of an electrical discharge tube
particle beam
a collimated flow of particles (atoms or electrons or molecules)
ion beam, ionic beam
a beam of ions moving in the same direction at the same speed
Type of:
electromagnetic radiation, electromagnetic wave, nonparticulate radiation
radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge

n a signal transmitted along a narrow path; guides airplane pilots in darkness or bad weather

radio beam
Type of:
sign, signal, signaling
any nonverbal action or gesture that encodes a message

v emit light; be bright, as of the sun or a light

“The fire beamed on their faces”
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beat down
shine hard
shine like a beacon
shine intensely
flame, flare
shine with a sudden light
shine brighter than
shine with a weak or fitful light
flick, flicker
shine unsteadily
shine brightly and intensively
scintillate, twinkle, winkle
emit or reflect light in a flickering manner
burn, glow
shine intensely, as if with heat
glare or strike with great intensity
burn unsteadily, feebly, or low; flicker

v broadcast over the airwaves, as in radio or television

air, broadcast, send, transmit
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broadcast or disseminate via satellite
broadcast a sports event
telecast, televise
broadcast via television
transmit (a signal) for setting off an appropriate response, as in telecommunication
rebroadcast, rerun
broadcast again, as of a film
colorcast, colourcast
broadcast in color
Type of:
air, bare, publicise, publicize
make public

v have a complexion with a strong bright color, such as red or pink

glow, radiate, shine
Type of:
appear, look, seem
give a certain impression or have a certain outward aspect

v experience a feeling of well-being or happiness, as from good health or an intense emotion

“She was beaming with joy”
glow, radiate, shine
Type of:
experience, feel
undergo an emotional sensation or be in a particular state of mind

v smile radiantly; express joy through one's facial expression

Type of:
change one's facial expression by spreading the lips, often to signal pleasure

v express with a beaming face or smile

“he beamed his approval”
Type of:
evince, express, show
give expression to

n the broad side of a ship

“they sighted land on the port beam
Type of:
an extended outer surface of an object

n (nautical) breadth amidships

Type of:
breadth, width
the extent of something from side to side

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