Is it ensure, insure, or assure?
Old English feorr "far, remote, distant, to a great distance, long ago," from Proto-Germanic *ferro (cf. Old Saxon ferr, Old Frisian fer, Old Norse fjarre, Dutch ver, Old High German ferro, German fern, Gothic fairra), from PIE *per- "through, across, beyond" (cf. Sanskrit parah "farther, remote, ulterior," Hittite para "outside of," Greek pera "across, beyond," Latin per "through," Old Irish ire "farther"). Far East "China, Japan, and surrounding regions" is from 1838.