Is it ensure, insure, or assure?
late 14c., from Old French repletion, replection (early 14c.) or directly from Late Latin repletionem (nominative repletio), noun of action from past participle stem of replere "to fill" (see replete).
repletion re·ple·tion (rĭ-plē'shən)
The condition of being fully supplied or completely filled.
A state of excessive fullness.