The Collaborative International Dictionary of English v.0.48:

Limber \Lim"ber\ v. t. [imp. & p. p. Limbered
   (l[i^]m"b[~e]rd); p. pr. & vb. n. Limbering.] (Mil.)
   To attach to the limber; as, to limber a gun.
   [1913 Webster]

   To limber up, to change a gun carriage into a four-wheeled
      vehicle by attaching the limber.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Limber \Lim"ber\, a. [Akin to limp, a. [root]125. See Limp,
   a.]
   Easily bent; flexible; pliant; yielding. --Milton.
   [1913 Webster]

         The bargeman that doth row with long and limber oar.
                                                  --Turbervile.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Limber \Lim"ber\ (l[i^]m"b[~e]r), n. [For limmer, Icel. limar
   branches, boughs, pl. of lim; akin to E. limb. See Limb a
   branch.]
   1. pl. The shafts or thills of a wagon or carriage. [Prov.
      Eng.]
      [1913 Webster]

   2. (Mil.) The detachable fore part of a gun carriage,
      consisting of two wheels, an axle, and a shaft to which
      the horses are attached. On top is an ammunition box upon
      which the cannoneers sit.
      [1913 Webster]

   3. pl. (Naut.) Gutters or conduits on each side of the
      keelson to afford a passage for water to the pump well.
      [1913 Webster]

   Limber boards (Naut.), short pieces of plank forming part
      of the lining of a ship's floor immediately above the
      timbers, so as to prevent the limbers from becoming
      clogged.

   Limber box or Limber chest (Mil.), a box on the limber
      for carrying ammunition.

   Limber rope, Limber chain or Limber clearer (Naut.), a
      rope or chain passing through the limbers of a ship, by
      which they may be cleared of dirt that chokes them.
      --Totten.

   Limber strake (Shipbuilding), the first course of inside
      planking next the keelson.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Limber \Lim"ber\, v. t.
   To cause to become limber; to make flexible or pliant.
   --Richardson.
   [1913 Webster]

WordNet (r) 3.0 (2006):

limber
    adj 1: (used of e.g. personality traits) readily adaptable; "a
           supple mind"; "a limber imagination" [syn: limber,
           supple]
    2: (used of artifacts) easily bent
    3: (used of persons' bodies) capable of moving or bending freely
       [syn: limber, supple]
    n 1: a two-wheeled horse-drawn vehicle used to pull a field gun
         or caisson
    v 1: attach the limber; "limber a cannon" [syn: limber,
         limber up]
    2: cause to become limber; "The violist limbered her wrists
       before the concert"