Meaning
hooray!, long live
- an exclamation of joy, celebration, or triumph
- an expression of enthusiasm or praise (often followed by 'la/il...')

In a sentence
Evviva, finalmente sono iniziate le vacanze!
Hooray, the holidays have finally started!
Abbiamo vinto la partita, evviva!
We won the match, hooray!
Evviva gli sposi!
Long live the newlyweds!
Usage notes
- Can also be used sarcastically to express mock enthusiasm.