The Passover Hagaddah (or Story) states that "Whoever does not say these three things has not fulfilled his obligation: Pesach, Matzah, Maror." Pesach is the pascal lamb offering that is no longer brought as the Temple in Jerusalem no longer stands. In the days of the Temple, thousands of lambs were slaughtered on the eve of Passover to be eaten that night along with the matzah and the maror, the bitter herb (traditionally, romaine lettuce or horseraddish). Today we eat only the matzah and maror.
Seder = סדר
night of passover
No. A Seder is a Jewish religious meal recalling the Passover.
Sometimes.
Four glasses of wine are drunk as part of the seder.
At the Seder meal we retell the story of the Exodus from Egypt.
Generally it occurs only during Passover, a Jewish holiday. There is also a seder for the holiday of Tu Bishvat, but this seder is rarely observed.
One of the foods on the Seder plate is the Z'roa - a roasted shank-bone of lamb or goat, or a chicken wing, or chicken neck. It symbolizes the korban Pesach (Pesach sacrifice), which was a lamb that was offered in the Temple in Jerusalem, then roasted and eaten as part of the meal on Seder night. See also:More abut the Seder meal
At sundown.
It is called a Seder, or "Order" in English
The oldest family member is supposed to read the story of the Exodus during the seder. For the meal part, the oldest man is responsible for reciting certain blessings.
Getting together with loved ones.