Mamma mia
interjection
Mam·ma mia ˈmä-mə-ˈmē-ə 
—used to express strong feeling (such as pleasure or surprise)
Mamma mia! My deepest wish has come true. I have a son!
R. Eugene Jackson
R. Eugene Jackson
Word History
Etymology
borrowed from Italian mammamìa, mamma mia, exclamation expressing annoyance, fatigue, fear, etc., literally "my mother!"
First Known Use
1860, in the meaning defined above