What is "erusin"

Erusin is the Hebrew term for betrothal. In modern Hebrew, "erusin" means engagement, but this is not the historical meaning of the term, which is the first part of marriage (the second part being nissuin).

Since the Middle Ages it is customary for the marriage to occur immediately after the betrothal, and to perform the betrothal during the marriage ceremony itself. Previously this was not the case, and there were often several months between the two events.

In Hebrew and classical rabbinic literature, betrothal is frequently referred to as sanctification (Hebrew: Kiddushin, קידושין), on account of the bride becoming "sanctified" (dedicated) to the groom.