Source : Webster's Revised Unabridged Dictionary (1913)

Survivorship \Sur*viv"or*ship\, n.
   1. The state of being a survivor.

   1. (Law) The right of a joint tenant, or other person who has
      a joint interest in an estate, to take the whole estate
      upon the death of other. --Blackstone.

   {Chance of survivorship}, the chance that a person of a given
      age has of surviving another of a giving age; thus, by the
      Carlisle tables of mortality the chances of survivorship
      for two persons, aged 25 and 65, are 89 and 11
      respectively, or about 8 to 1 that the elder die first.