beam

Pronunciation: /biːm/

Definition of beam

1a long, sturdy piece of squared timber or metal used to support the roof or floor of a building: there are very fine oak beams in the oldest part of the house the cottage boasts a wealth of exposed beams
a narrow, raised horizontal piece of squared timber on which a gymnast balances while performing exercises: a compulsory set of exercises on floor, vault, bars, and beam
a horizontal piece of squared timber or metal supporting the deck and joining the sides of a ship: the watertight skin and deck were put on over this framework of ribs and beams
Nautical the direction of an object visible from the port or starboard side of a ship when it is perpendicular to the centre line of the vessel:there was land in sight on the port beam
a ship’s breadth at its widest point:a cutter with a beam of 16 feet
informal the width of a person’s hips:notice how broad in the beam she’s getting?
the main stem of a stag’s antler: the wide beams sprouted ten main tines
the crossbar of a balance.
an oscillating shaft which transmits the vertical piston movement of a beam engine to the crank or pump.
the shank of an anchor.
historical the main timber of a horse-drawn plough.

2a ray or shaft of light:a beam of light flashed in front of her the torch beam dimmed perceptibly
a directional flow of particles or radiation:beams of electrons
a series of radio or radar signals emitted as a navigational guide for ships or aircraft: the detector simply pinpoints the radar beams that other ships transmit

1 [with object and adverbial of direction] transmit (a radio signal or broadcast) in a specified direction:the satellite beamed back radio signals to scientists on Earth
[with object] (beam someone up/down) (in science fiction) transport someone instantaneously to or from a spaceship: mission controller, beam me up!
[phrase from the American television series Star Trek]

2 [no object, with adverbial of direction] (of a light or light source) shine brightly:the sun’s rays beamed down

3 [no object] smile radiantly:she beamed with pleasure
[with object] express (an emotion) with a radiant smile:the instructress beamed her approval

Phrases

a beam in one's eye: a fault that is greater in oneself than in the person one is finding fault with: economic forecasters should consider the beam in their own eye before criticizing the government’s figures
[with biblical allusion to Matt. 7:3]
off (or way off) beam: informal on the wrong track; mistaken: you’re way off beam on this one
on the beam: informal on the right track: I’ve had a couple of stormy sessions with the old rascal trying to keep him on the beam
on her (or its) beam ends: (of a ship) heeled over on its side; almost capsized.
on one's beam ends: near the end of one’s resources; desperate: if they were on their beam ends they might brave an audience with Fisher

Old English bēam 'tree, beam', of West Germanic origin; related to Dutch boom and German Baum

Definition of beam in the US English dictionary