The shankbone, or the zeroa זרוע, is one of the three basic components of the Passover service.
In ancient times, the Israelites were commanded to sacrifice one lamb per family to eat for the Passover meal.
Today, we no longer sacrifice animals in Jewish worship. Instead we place a piece of roasted meat or bone on the seder plate to remind us of the pascal lamb.
Some people specifically use a different animal than lamb, such as a chicken neck, so no one will think that you violated the traditional prohibition and actually sacrificed a lamb. Others are not so concerned about this, and they pop on a shank bone ordered specially from their local butcher. And hey, veggies, don’t worry! According to traditional understanding of Passover rituals, you can also use a roasted beet as a vegetarian shankbone.
seder
Pronounced: SAY-der, Origin: Hebrew, literally “order”; usually used to describe the ceremonial meal and telling of the Passover story on the first two nights of Passover. (In Israel, Jews have a seder only on the first night of Passover.)