Is it ensure, insure, or assure?
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.