Is it ensure, insure, or assure?
1650s, "magnetically or electrically stimulated;" modern sense of "agitated" attested 1855; past participle adjective from excite. Related: Excitedly.
mid-14c., "to move, stir up, instigate," from Old French esciter (12c.) or directly from Latin excitare "rouse, call out, summon forth, produce," frequentative of exciere "call forth, instigate," from ex- "out" (see ex-) + ciere "set in motion, call" (see cite). Of feelings, from late 14c. Of bodily organs or tissues, from 1831. Main modern sense of "emotionally agitate" is first attested 1821.