It's a new record. Yamamoto's powers of Chunni know no bounds for the destruction of Waseda's glasses. I wonder how many more ways they can break. A Chunni really can be a fearsome problem child. Especially her.
@Tigana It was ダボ (dabo), which is considered slang but insults intelligence similarly to "baka." Brainlet isn't a great substitute since that's internet slang, while dabo is regional slang in Kansai. You can think of it like he said something like "numbskull."