condition precedent

from The Collaborative International Dictionary of English v.0.48

Precedent \Pre*ced"ent\, a. [L. praecedens, -entis, p. pr. of
   praecedere: cf. F. pr['e]c['e]dent. See {Precede}.]
   Going before; anterior; preceding; antecedent; as, precedent
   services. --Shak. "A precedent injury." --Bacon.
   [1913 Webster]

   {Condition precedent} (Law), a condition which precede the
      vesting of an estate, or the accruing of a right.
      [1913 Webster]