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)

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

a reappearance of an earlier characteristic

turning in the opposite direction

returning to a former state

a failure to maintain a higher state

reversion - thesaurus

atavism   backsliding   lapse   lapsing   regress   regression   relapse   relapsing   retrogression   retroversion   reversal   reverse   reverting   throwback   turnabout   turnaround