[1] : The Collaborative International Dictionary of English v.0.48

plumb \plumb\ plu^m, n. f. plomb, l. plumbum lead, a leaden
   ball or bullet; cf. gr. mo`lybos, mo`libos, mo`lybdos. cf.
   plummet, plunge.
   a little mass or weight of lead, or the like, attached to a
   line, and used by builders, etc., to indicate a vertical
   direction; a plummet; a plumb bob. see plumb line, below.
   1913 webster

   plumb bob. see bob, 4.

   plumb joint, in sheet-metal work, a lap joint, fastened by
      solder.

   plumb level. see under level.

   plumb line.
   a the cord by which a plumb bob is suspended; a plummet.
   b a line directed to the center of gravity of the earth.

   plumb rule, a narrow board with a plumb line, used by
      builders and carpenters.
      1913 webster
see also:
plummet plunge plumb line plumb bob bob plumb joint 
plumb level level plumb rule 

[2] : The Collaborative International Dictionary of English v.0.48

level \lev"el\ le^v"e^l, n. oe. level, livel, of. livel,
   f. niveau, fr. l. libella level, water level, a plumb level,
   dim. of libra pound, measure for liquids, balance, water
   poise, level. cf. librate, libella.
   1. a line or surface to which, at every point, a vertical or
      plumb line is perpendicular; a line or surface which is
      everywhere parallel to the surface of still water; -- this
      is the true level, and is a curve or surface in which all
      points are equally distant from the center of the earth,
      or rather would be so if the earth were an exact sphere.
      1913 webster

   2. a horizontal line or plane; that is, a straight line or a
      plane which is tangent to a true level at a given point
      and hence parallel to the horizon at that point; -- this
      is the apparent level at the given point.
      1913 webster

   3. an approximately horizontal line or surface at a certain
      degree of altitude, or distance from the center of the
      earth; as, to climb from the level of the coast to the
      level of the plateau and then descend to the level of the
      valley or of the sea.
      1913 webster

            after draining of the level in northamptonshire.
                                                  --sir m. hale.
      1913 webster

            shot from the deadly level of a gun.  --shak.
      1913 webster

   4. hence, figuratively, a certain position, rank, standard,
      degree, quality, character, etc., conceived of as in one
      of several planes of different elevation.
      1913 webster

            providence, for the most part, sets us on a level.
                                                  --addison.
      1913 webster

            somebody there of his own level.      --swift.
      1913 webster

            be the fair level of thy actions laid
            as temperance wills and prudence may persuade.
                                                  --prior.
      1913 webster

   5. a uniform or average height; a normal plane or altitude; a
      condition conformable to natural law or which will secure
      a level surface; as, moving fluids seek a level.
      1913 webster

            when merit shall find its level.      --f. w.
                                                  robertson.
      1913 webster

   6. mech.  surv.
      a an instrument by which to find a horizontal line, or
          adjust something with reference to a horizontal line.
      b a measurement of the difference of altitude of two
          points, by means of a level; as, to take a level.
          1913 webster

   7. a horizontal passage, drift, or adit, in a mine.
      1913 webster

   air level, a spirit level. see spirit level below.

   box level, a spirit level in which a glass-covered box is
      used instead of a tube.

   carpenter's level, mason's level, either the plumb level
      or a straight bar of wood, in which is imbedded a small
      spirit level.

   level of the sea, the imaginary level from which heights
      and depths are calculated, taken at a mean distance
      between high and low water.

   line of levels, a connected series of measurements, by
      means of a level, along a given line, as of a railroad, to
      ascertain the profile of the ground.

   plumb level, one in which a horizontal bar is placed in
      true position by means of a plumb line, to which it is at
      right angles.

   spirit level, one in which the adjustment to the horizon is
      shown by the position of a bubble in alcohol or ether
      contained in a nearly horizontal glass tube, or a circular
      box with a glass cover.

   surveyor's level, a telescope, with a spirit level
      attached, and with suitable screws, etc., for accurate
      adjustment, the whole mounted on a tripod, for use in
      leveling; -- called also leveling instrument.

   water level, an instrument to show the level by means of
      the surface of water in a trough, or in upright tubes
      connected by a pipe.
      1913 webster
see also:
librate libella air level a spirit level spirit level box level 
carpenter's level mason's level level of the sea line of levels plumb level 
surveyor's level leveling instrument water level 

[3] : WordNet (r) 2.0

plumb level
     n : a carpenter's level with a plumb line at right angles to it

Plumb >> P Words
Plumb, definition of term: Plumb
plumb_pag1.html

Level >> L Words
Level, definition of term: Level
level_pag1.html

Plumb Line >> P Words
Plumb Line, definition of term: Plumb Line
plumb+line_pag1.html

Plumb Bob >> P Words
Plumb Bob, definition of term: Plumb Bob
plumb+bob_pag1.html

Level Off >> L Words
Level Off, definition of term: Level Off
level+off_pag1.html

Level Crossing >> L Words
Level Crossing, definition of term: Level Crossing
level+crossing_pag1.html