Jubilate

Webster's Dictionary

(1): ( n.) The third Sunday after Easter; - so called because the introit is the 66th Psalm, which, in the Latin version, begins with the words, "Jubilate Deo."

(2): ( n.) A name of the 100th Psalm; - so called from its opening word in the Latin version.

(3): ( v. i.) To exult; to rejoice.