[beam] n [ME beem, fr. OE beam tree, beam; akin to OHG boum tree] (bef. 12c) 1 a: a long piece of heavy often squared timber suitable for use in construction b: a wood o r metal cylinder in a loom on which the warp 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 ~ supporting a floor"; also: boom, spar "the ~ of a crane" f: the extreme width of a ship at the widest part g: an oscillating lever on a central axis receiving motion at one end from an engine piston rod and transmitting it at the other
2. a: a ray or shaft of light b: a collection of nearly parallel rays (as X rays) or a stream of particles (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 -- on the beam 1: following a guiding beam
2: proceeding or operating correctly
[2]beam vt (15c) 1: to emit in beams or as a beam
2: to support with beams 3 a: to aim and transmit (a broadcast) by directional antennas or by satellite b: to direct to a particular audience ~ vi 1: to send out beams of light
2: to smile with joy