slander
譖 centers on false speech intended to harm someone's reputation: slander.
譖 combines 言 (speech) with 朁, which likely contributes the sound and may relate to cutting or piercing, suggesting harmful words.
The left side 言 is speech, and the right side 朁 looks like a sharp tool. Imagine words used like a knife to cut someone down with slander.
For シン, picture a sinister person spreading slander: sin -> シン, and their sharp words harm others.