Is it ensure, insure, or assure?
1550s, from Middle French claudication (13c.) or directly from Latin claudicationem (nominative claudicatio) "a limping," noun of action from past participle stem of claudicare "to limp, be lame," from claudus "limping, halting, lame." Related: Claudicant (adj.); claudicate.
claudication clau·di·ca·tion (klô'dĭ-kā'shən)
A halt or lameness in a person's walk; a limp.