Subject to be defeated, annulled, revoked, or undone upon the hap-pening of a future event or the performance of a condition subsequent, or hy a condi-tional limitation. Usually spoken of estates and Interests in land. For instance, a mortgagee’s estate is defeasible (liable to he de-feated) by the mortgagor’s equity of redemption
Source: Black's Law Dictionary 2nd Ed (1910)
