a small piece of paper that children roll into a ball and then spit or throw at each other 〔儿童互相投掷的〕唾沫湿纸团
Examples from the Corpus
spitball• My memos are spitballs in the face of the facelessmonolith where I work.• The Operations students - the field men - are called spitballs around here.• I checked around for spitballs and paper wads.• The other buildings are schoolrooms and a gymnasium for the spitballs and gut-men.• Anna said they are the ones who score low grades and throw spitballs in class.