Is it ensure, insure, or assure?
1520s, altered from stakeren (c.1300), from Old Norse stakra or Old Danish stagra, both "to push, stagger." Cognate with Dutch staggelen "to stagger," German staggeln "to stammer." Transitive sense of "bewilder, amaze" first recorded 1550s; that of "arrange in a zig-zag pattern" is from 1856. Related: Staggered; staggering.