ushpizin
"Guests" (Aramaic); mythic guests invited to the sukkah.
Yizkor
"Remember;" memorial service held on Yom Kippur and on the last day of Pesach, Shavout, and Sukkot.
Arbaah minim
Literally, “four species.” The Torah specifies four species to bring together on Sukkot. The four species are: lulav (branches of palm trees), etrog (citron), hadasim (myrtle branches), and aravot (willows) (Leviticus 23:40).
Why is caring for the environment emphasized on Tu BiShvat?
Tu BiShvat is a minor festival whose provenance dates only to the time of the Second Temple. However, the kabbalists who clustered around the great fifteenth-century mystic Isaac Luria of Safed placed great weight on the holiday, creating new festivities, gatherings at which hymns were sung, fruit (particularly carob) was eaten, and four cups of wine were taken (as in the Passover seder).