Is it ensure, insure, or assure?
late 15c., "recovery or regaining of things," from Latin recuperationem (nominative recuperatio) "a getting back, regaining, recovery," noun of action from past participle stem of recuperare "get back, regain, get again," in Medieval Latin "revive, convalesce, recover," related to recipere (see receive). Meaning "restoration to health or vigor" is from 1865.
1540s, from Latin recuperatus, past participle of recuperare "to get again," in Medieval Latin "revive, convalesce, recover" (see recuperation). Meaning "to recover from sickness or loss" is from 1864. Related: Recuperated; recuperating.
recuperate re·cu·per·ate (rĭ-kōō'pə-rāt', -kyōō'-)
v. re·cu·per·at·ed, re·cu·per·at·ing, re·cu·per·ates
To return to health or strength; recover.