viva (interj.)
1640s, from Italian viva "(long) live, may he (or she) live," third person singular present subjunctive of vivere "to live," from Latin vivere "to live," from PIE root *gwei- "to live." Probably reborrowed (1836) from Spanish viva, from vivir "to live," from Latin vivere. Sometimes also in Latin form vivat (1660s).