The verb undermine is to weaken, subvert, or make something less strong by attacking or removing its supporting materials or foundation.

Synonyms are cripple, sabotage, enfeeble, or compromise.

The word origins from the 1300s undermyne meaning “render unstable by digging at the foundation”, from under + mine. The figurative sense “injure by invisible, secret, or dishonourable means” is attested from the early 15th century.

It was designed to help with the country’s undermining economic position.

The continuous heavy rain has undermined the soil, causing a serious landslide.

This fact alone could undermine his years of hard work, so he better fix himself.