A farrago is a pile of odds and ends or a random assortment of stuff.
If your teacher said your paper was a farrago of thoughts, that's not good: a farrago is a disorganized mix of things that don't fit together. Farrago sounds more formal than hodgepodge or mishmash, but it means about the same thing. A flea market usually features a farrago of antiques and old junk. And kids get a farrago of treats — chocolates, lollipops, the occasional box of raisins — on Halloween.