1853, from Fr. fianceé, fem. of fiancé, pp. of fiancer "betrothed," from O.Fr. fiancer, from fiance "a promise, trust," from fier "to trust," from V.L. *fidare (see affiance). Has all but expelled native betrothed. The verb fiance, now obsolete, was used c.1450-1600 for "to engage to be married."
[fee-ahn-sey, fee-ahn-sey] 
