I love pizza. I'm actually eating it now.
I just ate pizza! its a traditional italian dish! 
When was it invented?
Good question, what i do know is that the term "pizza" was first recorded in the 10 century, from the southern italian town of Gaeta, Lazio. So i'd imagine around then! 
Do you know where the word originated from?
"Pizza" was actually recorded at that time (10th century) but it was recorded in a latin manuscript and later translated.