The Collaborative International Dictionary of English v.0.48:

Walker \Walk"er\, n.
   1. One who walks; a pedestrian.
      [1913 Webster]

   2. That with which one walks; a foot. [Obs.]
      [1913 Webster]

            Lame Mulciber, his walkers quite misgrown.
                                                  --Chapman.
      [1913 Webster]

   3. (Law) A forest officer appointed to walk over a certain
      space for inspection; a forester.
      [1913 Webster]

   4. [AS. wealcere. See Walk, v. t., 3.] A fuller of cloth.
      [Obs. or Prov. Eng. & Scot.]
      [1913 Webster]

            She cursed the weaver and the walker
            The cloth that had wrought.           --Percy's
                                                  Reliques.
      [1913 Webster]

   5. (Zool.) Any ambulatorial orthopterous insect, as a stick
      insect.
      [1913 Webster]

   6. (construction, tunneling) A shift superintendent or
      assistant superintendent who supervises several
      shifters[4] and their crews. Since these crews are usually
      separated by some distance, the walker is frequently seen
      walking between them. Also called walking boss.
      [RDH]

   7. A low frame having casters or wheels, designed to enclose
      a baby on its sides and provide support while the baby is
      learning to walk; it usually has a seat so that the baby
      can sit while not walking.

   Syn: go-cart, baby-walker.
        [PJC]

   8. A low rectangular frame of light metal about waist high,
      usually having two horizontal arms mounted on four legs
      with an open rear, designed to be carried or pushed in
      front of a person whose legs are impaired, to provide
      support while walking; it may have wheels on two of the
      four legs.
      [PJC]