Other forms: calumnies
Use the noun calumny to characterize verbal attacks that are meant to destroy reputations or friendships. You've probably seen political ads during election time that rely on calumny to move voters.
Calumny comes from the Latin word calvi, meaning "to trick, deceive," which is why it can also describe falsely accusing someone or quoting them out of context with the intent to do them harm. Some political candidates use this tactic against opponents in the hope that voters will be tricked into thinking that the accusations are true.