Kol Nidre
noun
Kol Ni·dre kōl-ˈni-(ˌ)drā 
kȯl-,
-drə;
-ni-ˈdrā
: a formula for the annulment of private vows chanted in the synagogue on the eve of Yom Kippur
Word History
Etymology
Aramaic kol nidhrē all the vows; from the opening phrase of the prayer
First Known Use
1881, in the meaning defined above