reversion

(noun) (law) an interest in an estate that reverts to the grantor (or his heirs) at the end of some period (e.g., the death of the grantee).

(noun) (genetics) a return to a normal phenotype (usually resulting from a second mutation).

(noun) a reappearance of an earlier characteristic. Synonyms: atavism, throwback.

(noun) turning in the opposite direction. Synonyms: reverse, reversal, turnabout, turnaround.

(noun) returning to a former state. Synonyms: regression, regress, retrogression, retroversion.

(noun) a failure to maintain a higher state. Synonyms: backsliding, lapse, lapsing, relapse, relapsing, reverting.