Definitions for hallelˈhɑ leɪl, hɑˈleɪl
Random House Webster's College Dictionary
Hal•lelˈhɑ leɪl, hɑˈleɪl(n.)
a Hebrew liturgical prayer consisting of all or part of Psalms 113–118, recited at the beginning of each new month of the Jewish calendar and on various festivals, as Passover and Hanukkah.
Origin of Hallel:
1695–1705; < Heb hallēl praise
(Judaism) a chant of praise (Psalms 113 through 118) used at Passover and Shabuoth and Sukkoth and Hanukkah and Rosh Hodesh
The Nuttall Encyclopedia
name given to Psalms cxiii.-cxviii. chanted by the Jews at their great annual festivals.