Is it ensure, insure, or assure?
"to limit, restrain, to be sparing or frugal," Old English styntan "to blunt, make dull," from Proto-Germanic *stuntijanan (cf. Old Norse stuttr "short, scant," Middle High German stunz "blunt, short," German stutzen "to cut short, curtail, stop, hesitate"), from PIE root *(s)teu- "to beat, strike, push, thrust" (see steep (adj.)). Related: Stinted; stinting. The noun is attested from c.1300.