诽

words (讠) + wrong (非) = slanderous speech

讠marks this as something spoken; 非 gives the sound fěi and carries a secondary sense of wrongness or negation, which fits slander well even if its role here is primarily phonetic.

他说的那些话是对我的诽谤。

在网上散布诽谤他人的内容是违法的。