WordWeb Online

1. Joyful and proud especially because of triumph or success
   "jubilant crowds filled the streets on VJ Day"
   - exultant, exulting, prideful, rejoicing, triumphal, triumphant
    
2. Full of high-spirited delight
   "a jubilant heart"
   - elated, gleeful, joyful, cock-a-hoop, on top of the world

See also: elated, joyous, jubilancy, jubilantly, jubilate