Hamentaschen = Cookies traditionally made for Purim that resemble a 3-cornered hat.
Purim = Jewish holiday commemorating a time in ancient Persia when Jewish people were saved from a plot to annihilate all the Jews.
Pesach = Passover. Jewish holiday commemorating exodus from Egypt.
Rosh Hashanah = Jewish new year.
Shabbat = Jewish Sabbath. Starts at sunset Friday night through nightfall Saturday night. Every week.
Shabbos = alternate pronunciation of Shabbat.
Shalach Manos = Gifts of food given on Purim. Also called Mishloach Manot.
Shavuos = alternate pronunciation of Shavuot.
Shavuot = Jewish holiday celebrating the receiving of the Torah at Mt. Sinai.