term:

Revert

revert vi

1 : to come or go back (as to a former status or state) [if the donee of a general power fails to exercise it…the appointive assets to the donor’s estate “W. M. McGovern, Jr. et al.“]
2 : to return to the grantor or his or her heirs as a reversion
re·vert·ible [-vər-tə-bəl]
adj