JUBILATE

Ju′bi‐la″te (?), n. [[L., imperat. of jubilare to shout for joy.]] 1. 1. 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. 2. A name of the 100th Psalm; — so called from its opening word in the Latin version.