The Collaborative International Dictionary of English v.0.48:

Pintle \Pin"tle\, n. [A diminutive of Pin.]
   1. A little pin.
      [1913 Webster]

   2. (Mech.) An upright pivot pin; as:
      (a) The pivot pin of a hinge.
      (b) A hook or pin on which a rudder hangs and turns.
      (c) A pivot about which the chassis swings, in some kinds
          of gun carriages.
      (d) A kingbolt of a wagon.
          [1913 Webster]

WordNet (r) 3.0 (2006):

pintle
    n 1: a pin or bolt forming the pivot of a hinge

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "pintle":
   arbor, axis, axle, axle bar, axle shaft, axle spindle, axle-tree,
   distaff, fulcrum, gimbal, gudgeon, hinge, hingle, hub, mandrel,
   nave, oarlock, pin, pivot, pole, radiant, rowlock, spindle, swivel,
   trunnion