Dimensional lumber

Lumber \Lum"ber\, n. [Prob. fr. Lombard, the Lombards being the
   money lenders and pawnbrokers of the Middle Ages. A lumber
   room was, according to Trench, originally a Lombard room, or
   room where the Lombard pawnbroker stored his pledges. See
   {Lombard}.]
   1. A pawnbroker's shop, or room for storing articles put in
      pawn; hence, a pledge, or pawn. [Obs.]
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            They put all the little plate they had in the
            lumber, which is pawning it, till the ships came.
                                                  --Lady Murray.
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   2. Old or refuse household stuff; things cumbrous, or bulky
      and useless, or of small value.
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   3. Timber sawed or split into the form of beams, joists,
      boards, planks, staves, hoops, etc.; esp., that which is
      smaller than heavy timber. [U.S.]
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   {Lumber kiln}, a room in which timber or lumber is dried by
      artificial heat. [U.S.]

   {Lumber room}, a room in which unused furniture or other
      lumber is kept. [U.S.]

   {Lumber wagon}, a heavy rough wagon, without springs, used
      for general farmwork, etc.

   {dimensional lumber}, lumber, usually of pine, which is sold
      as beams or planks having a specified nominal
      cross-section, usually in inches, such a two-by-four,
      two-by-six, four-by-four, etc.
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Dimension \Di*men"sion\, n. [L. dimensio, fr. dimensus, p. p. of
   dimetiri to measure out; di- = dis- + metiri to measure: cf.
   F. dimension. See {Measure}.]
   1. Measure in a single line, as length, breadth, height,
      thickness, or circumference; extension; measurement; --
      usually, in the plural, measure in length and breadth, or
      in length, breadth, and thickness; extent; size; as, the
      dimensions of a room, or of a ship; the dimensions of a
      farm, of a kingdom.
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            Gentlemen of more than ordinary dimensions. --W.
                                                  Irving.
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   {Space of dimension}, extension that has length but no
      breadth or thickness; a straight or curved line.

   {Space of two dimensions}, extension which has length and
      breadth, but no thickness; a plane or curved surface.

   {Space of three dimensions}, extension which has length,
      breadth, and thickness; a solid.

   {Space of four dimensions}, as imaginary kind of extension,
      which is assumed to have length, breadth, thickness, and
      also a fourth imaginary dimension. Space of five or six,
      or more dimensions is also sometimes assumed in
      mathematics.
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   2. Extent; reach; scope; importance; as, a project of large
      dimensions.
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   3. (Math.) The degree of manifoldness of a quantity; as, time
      is quantity having one dimension; volume has three
      dimensions, relative to extension.
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   4. (Alg.) A literal factor, as numbered in characterizing a
      term. The term dimensions forms with the cardinal numbers
      a phrase equivalent to degree with the ordinal; thus,
      a^{2}b^{2}c is a term of five dimensions, or of the fifth
      degree.
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   5. pl. (Phys.) The manifoldness with which the fundamental
      units of time, length, and mass are involved in
      determining the units of other physical quantities.

   Note: Thus, since the unit of velocity varies directly as the
         unit of length and inversely as the unit of time, the
         dimensions of velocity are said to be length [divby]
         time; the dimensions of work are mass [times]
         (length)^{2} [divby] (time)^{2}; the dimensions of
         density are mass [divby] (length)^{3}.

   {Dimensional lumber}, {Dimension lumber}, {Dimension
   scantling}, or {Dimension stock} (Carp.), lumber for
      building, etc., cut to the sizes usually in demand, or to
      special sizes as ordered.

   {Dimension stone}, stone delivered from the quarry rough, but
      brought to such sizes as are requisite for cutting to
      dimensions given.
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