Source : Webster's Revised Unabridged Dictionary (1913)

Jubilate \Ju`bi*la"te\, n. [L., imperat. of jubilare to shout
   for joy.]
   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. A name of the 100th Psalm; -- so called from its opening
      word in the Latin version.

Jubilate \Ju"bi*late\, v. i. [L. jubilatus, p. p. of jubilare.]
   To exult; to rejoice. [R.] --De Quincey.

Source : WordNet®

jubilate
     v 1: celebrate a jubilee
     2: to express great joy; "Who cannot exult in Spring?" [syn: {exult},
         {rejoice}, {triumph}]