The Collaborative International Dictionary of English v.0.48:

Passing \Pass"ing\, n.
   The act of one who, or that which, passes; the act of going
   by or away.
   [1913 Webster]

   Passing bell, a tolling of a bell to announce that a soul
      is passing, or has passed, from its body (formerly done to
      invoke prayers for the dying); also, a tolling during the
      passing of a funeral procession to the grave, or during
      funeral ceremonies. --Sir W. Scott. --Longfellow.
      [1913 Webster]