saper

Je dois me saper.

I have to dress up.

Ce type-là est toujours bien sapé.

That guy is always well-dressed.

Cela va saper notre crédibilité.

This will erode our credibility.

Lyssenko croyait que la génétique moderne était un complot impérialiste occidental conçu pour saper la Russie.

Lysenko believed that modern genetics was a Western imperialist plot designed to undermine Russia.