Definition: A phrase that means "and so forth" or "on and on;" it usually refers to something that is a minor detail or boring and repetitive.
1) Our history teacher told us about the Civil War, the shoelace tax of 1876, the election of 1880, yadda yadda yadda.
2) Jenna told me every single detail about her trip -- how big her room was, where she sat on the plane, yadda yadda yadda.
Etymology: This phrase comes from Yiddish, and became popular in the 1990's after it was featured on the popular TV show "Seinfeld."
Synonyms: blah blah blah