Definition of yada yada yada exclamation from the Oxford Advanced Learner's Dictionary

yada yada yada

exclamation (also yadda yadda yadda)
ˌjædə jædə ˈjædə
; ˌjædə jædə ˈjædə
(North American English, informal)
used when you are talking about something to show that some of the details are not worth saying because they are not important or are boring or obviousHis new girlfriend is attractive, funny, smart, yada yada yada.