substitution

noun | \ ˌsəb-stə-ˈtü-shən, -ˈtyü- \ | sub·sti·tu·tion
  1. a : a disposition not in trust by which a donee, heir, or legatee is charged to hold property transferred and return it to a third person — compare fidei commissum, vulgar substitution

    Note: Substitutions are prohibited.

    b : replacement of a party to an action with a successor or representative upon motion to the court when the party is unable to continue litigating (as because of death, incompetency, transfer of interest, or loss of the office for which the party was suing or being sued in an official capacity)

    c : the replacement of a new agreement or obligation for an old one — see also novation