Source : Webster's Revised Unabridged Dictionary (1913)

Abaft \A*baft"\ ([.a]*b[.a]ft"), prep. [Pref. a- on + OE. baft,
   baften, biaften, AS. be[ae]ftan; be by + [ae]ftan behind. See
   {After}, {Aft}, {By}.] (Naut.)
   Behind; toward the stern from; as, abaft the wheelhouse.

   {Abaft the beam}. See under {Beam}.

Beam \Beam\, n. [AS. be['a]m beam, post, tree, ray of light;
   akin to OFries. b[=a]m tree, OS. b?m, D. boom, OHG. boum,
   poum, G. baum, Icel. ba?mr, Goth. bahms and Gr. ? a growth, ?
   to become, to be. Cf. L. radius staff, rod, spoke of a wheel,
   beam or ray, and G. strahl arrow, spoke of a wheel, ray or
   beam, flash of lightning. ?97. See {Be}; cf. {Boom} a spar.]
   1. Any large piece of timber or iron long in proportion to
      its thickness, and prepared for use.

   2. One of the principal horizontal timbers of a building or
      ship.

            The beams of a vessel are strong pieces of timber
            stretching across from side to side to support the
            decks.                                --Totten.

   3. The width of a vessel; as, one vessel is said to have more
      beam than another.

   4. The bar of a balance, from the ends of which the scales
      are suspended.

            The doubtful beam long nods from side to side.
                                                  --Pope.

   5. The principal stem or horn of a stag or other deer, which
      bears the antlers, or branches.

   6. The pole of a carriage. [Poetic] --Dryden.

   7. A cylinder of wood, making part of a loom, on which
      weavers wind the warp before weaving; also, the cylinder
      on which the cloth is rolled, as it is woven; one being
      called the fore beam, the other the back beam.

   8. The straight part or shank of an anchor.

   9. The main part of a plow, to which the handles and colter
      are secured, and to the end of which are attached the oxen
      or horses that draw it.

   10. (Steam Engine) A heavy iron lever having an oscillating
       motion on a central axis, one end of which is connected
       with the piston rod from which it receives motion, and
       the other with the crank of the wheel shaft; -- called
       also {working beam} or {walking beam}.

   11. A ray or collection of parallel rays emitted from the sun
       or other luminous body; as, a beam of light, or of heat.

             How far that little candle throws his beams !
                                                  --Shak.

   12. Fig.: A ray; a gleam; as, a beam of comfort.

             Mercy with her genial beam.          --Keble.

   13. One of the long feathers in the wing of a hawk; -- called
       also {beam feather}.

   {Abaft the beam} (Naut.), in an arc of the horizon between a
      line that crosses the ship at right angles, or in the
      direction of her beams, and that point of the compass
      toward which her stern is directed.

   {Beam center} (Mach.), the fulcrum or pin on which the
      working beam of an engine vibrates.

   {Beam compass}, an instrument consisting of a rod or beam,
      having sliding sockets that carry steel or pencil points;
      -- used for drawing or describing large circles.

   {Beam engine}, a steam engine having a working beam to
      transmit power, in distinction from one which has its
      piston rod attached directly to the crank of the wheel
      shaft.

   {Before the beam} (Naut.), in an arc of the horizon included
      between a line that crosses the ship at right angles and
      that point of the compass toward which the ship steers.

   {On the beam}, in a line with the beams, or at right angled
      with the keel.

   {On the weather beam}, on the side of a ship which faces the
      wind.

   {To be on her beam ends}, to incline, as a vessel, so much on
      one side that her beams approach a vertical position.