suru verb (special), transitive verb
slander; defame; calumniate
Rare, literary verb for making false and damaging statements about someone. Modern Japanese more often uses 中傷する or 悪口を言う.
彼は政敵を讒するような手紙を送ったと伝えられている。
He is said to have sent letters slandering his political rivals.
In classical literature, there are sometimes scenes where a retainer slanders their lord.