The Collaborative International Dictionary of English v.0.48:

Jubilant \Ju"bi*lant\, a. [L. jubilans, -antis, p. pr. of
   jubilare to shout for joy: cf. F. jubilant. See Jubilate.]
   Uttering songs of triumph; shouting with joy; triumphant;
   exulting. "The jubilant age." --Coleridge.
   [1913 Webster]

         While the bright pomp ascended jubilant. --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

jubilant
    adj 1: joyful and proud especially because of triumph or
           success; "rejoicing crowds filled the streets on VJ Day";
           "a triumphal success"; "a triumphant shout" [syn:
           exultant, exulting, jubilant, prideful,
           rejoicing, triumphal, triumphant]
    2: full of high-spirited delight; "a joyful heart" [syn:
       elated, gleeful, joyful, jubilant]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "jubilant":
   bursting with happiness, carried away, cock-a-hoop, crowing,
   delighting, ecstatic, elate, elated, enchanted, enraptured,
   enravished, entranced, exalted, exultant, exulting, flushed,
   freaked out, gloating, high, imparadised, in ecstasies, in heaven,
   in high feather, in paradise, in raptures, in seventh heaven,
   on cloud nine, overjoyed, overjoyful, possessed, rapt, raptured,
   rapturous, ravished, rejoicing, rhapsodic, sent, transported,
   triumphal, triumphant, whoop