godan verb (-ru), transitive verb
slander; libel; criticize harshly
Used for publicly or strongly speaking ill of someone, often with a nuance of unjust or malicious criticism. More formal and less common in everyday speech than 悪口を言う or 非難する.
彼は新聞で政治家をそしった。
He slandered the politician in the newspaper.
人をそしる前に、自分の行いを振り返るべきだ。
Before criticizing others, you should reflect on your own actions.