Is it ensure, insure, or assure?
Old English ford "shallow place where water can be crossed," from Proto-Germanic *furdhus (cf. Old Frisian forda, Old High German furt, German Furt "ford"), from PIE *prtu- "a going, a passage" (cf. Latin portus "harbor," originally "entrance, passage;" Old Welsh rit, Welsh rhyd "ford;" Old English faran "to go;" see port (n.1)). The line of automobiles is named for U.S. manufacturer Henry Ford (1863-1947).
1610s, from ford (n.). Related: Forded; fording.
Mention is frequently made of the fords of the Jordan (Josh. 2:7; Judg. 3:28; 12:5, 6), which must have been very numerous; about fifty perhaps. The most notable was that of Bethabara. Mention is also made of the ford of the Jabbok (Gen. 32:22), and of the fords of Arnon (Isa. 16:2) and of the Euphrates (Jer. 51:32).