Definition of: beam

(bēm) noun
1. A long, horizontal piece of wood, stone, or metal, forming part of the frame of a building or other structure.
2. The bar of a balance.
3. Naut. a One of the heavy pieces of timber or iron set transversely across a vessel to support the decks and stay the sides. b The greatest width of a vessel.
4. The widest part of anything.
5. A horizontal cylindrical bar, in a loom, upon which warp or woven goods are wound.
6. The pole of a carriage.
7. Mech. A horizontal bar that transmits power to the crankshaft through the connecting rod.
8. Optics A ray of light, or a group of nearly parallel rays.
9. Aeron. A continuous radio signal from a flying field to guide incoming pilots: also radio beam.
10. The main stem of a deer's antler.
11. The area of maximum sound clarity in front of a microphone.
12. The horizontal piece in a plow to which the share and the handles are attached.
13. A trough containing lights in the ceiling of a stage.
—off the beam
1. Aeron. Not following the radio beam.
2. Slang On the wrong track; wrong.
—on the beam
1. Naut. In a direction at right angles with the keel; abeam.
2. Aeron. Following the radio beam.
3. Slang In the right direction; just right; correct.
—v.t.
1. To send out in or as in beams or rays.
2. In radio, to aim or transmit (a signal) in a specific direction: to beam a program to France.
3. Aeron. To guide (an airplane) to a destination by means of radio beams.
—v.i.
4. To emit light.
5. To smile or grin radiantly. [OE, tree]
—beamed adjective
—beam′less adjective
—beam′like′ adjective