The most recent term was in terrorem, which is defined as:
Latin meaning "in fear." This phrase is used to describe provisions in contracts or wills meant to scare a person into complying with the terms of the agreement. For example, a will might state that an heir will forfeit her inheritance if she challenges the validity of the will. Of course, if the will is challenged and found to be invalid, then the clause itself is also invalid and the heir takes whatever she would have inherited if there were no will.
Edward Wiest got it right!
Today's term is:
effluxion of time.
As always, no dictionaries, please.