Source : Webster's Revised Unabridged Dictionary (1913)

Rundle \Run"dle\, n. [E. round. Cf. {Rondle}.]
   1. A round; a step of a ladder; a rung. --Duppa.

   2. A ball. [Obs.] --Holland.

   3. Something which rotates about an axis, as a wheel, or the
      drum of a capstan. ``An axis or cylinder having a rundle
      about it.'' --Bp. Wilkins.

   4. (Mach.) One of the pins or trundles of a lantern wheel.

Source : WordNet®

rundle
     n : one of the crosspieces that form the steps of a ladder [syn:
          {spoke}, {rung}]