rehab

1530s, "act of reinstating in a former rank or standing," from French réhabilitation and directly from Medieval Latin rehabilitationem (nominative rehabilitatio) "restoration," noun of action from past-participle stem of rehabilitare, from re- "again" (see re-) + habitare "make fit," from Latin habilis "easily managed, fit" (see able). Meaning "action of restoring anything to a previous condition" is by 1858. Specifically of criminals, addicts, etc., retrained for society from 1940.

1580s, "restore to a former capacity or standing, or a former right, rank, or privilege lost or forfeited," a back-formation from rehabilitation and in part from Medieval Latin rehabilitatus, past participle of rehabilitare. Century Dictionary calls it "a term drawn from the civil and canon law."

By 1845 as "to bring back to a former condition after decay or damage." The meaning "to restore one's reputation or character in the esteem of others" is from 1847. Related: Rehabilitated; rehabilitating.