Is it ensure, insure, or assure?
early 14c., "to cover (a street) with stones or other material," from Old French paver "to pave" (12c.), perhaps a back-formation from Old French pavement or else from Vulgar Latin *pavare, from Latin pavire "to beat, ram, tread down," from PIE *pau- "to cut, strike, stamp" (cf. Latin putare "to prune;" Greek paiein "to strike;" Lithuanian piauju "to cut," piuklas "saw"). Related: Paved; paving. The figurative sense of "make smooth" (as in pave the way) is attested from 1580s.