Likkutei Sichos Dictionary
The following sites have Yiddish dictionaries:
Zayin: The 7th letter of the Hebrew alphabet.
Z'chus: merit, pl. zechusim
Zeh L’umas zeh: (״את זה לעומת זה עשה האלקים״): “G-d created forces (kelipah - evil ) that oppose (holinesss)” (in order for man to have free-choice)
Zeir Anpin ("the small face" Aramaic): Ze'ir Anpin is the partzuf of the midot, corresponding to the emotive faculties of the soul. In general, the concept of "finitude" or "finite power" is identified with Ze'ir Anpin. See Arich Anpin.
Zivug ("coupling"): See Bashert, An idiom for marital relations.
Z'L: Hebrew initials of the words Zechorono LeVaracha (His memory is a blessing.)
Zmira pl. Zmirot: Songs with words
Zohar: The seminal work of the Kabbalah, written by Rabbi Shimon bar Yochai (2nd century) and his students. It is one of the basic texts of the oral Torah and Kabbalah. The Zoharic literature includes the Zohar proper, the Tikunei Zohar, and the Zohar Chadash.
Zot Chanukah: "The Dedication" The name associated with the last day of Chanukah.
ZT'L: Hebrew initials of the words Zechor Tzaddik LeVaracha (The memory of a Tzaddik - Righteous person is a blessing.)
ZTvK'L: Hebrew initials of the words Zechor Tzaddik veKadosh LeVaracha (The memory of a Tzaddik - Righteous man and a Kodosh - a holy man is a blessing)