c. 1600, "renew with regard to any state or quality," from re- "back," here "to a former condition," + integrate (v.). The sense of "make whole again, bring back to an integral condition" is from 1620s. The classically correct form is redintegrate (early 15c.). Earlier in a now-obsolete sense of "reinstate oneself" (1580s). Related: Reintegrated; reintegrating; reintegration.