salt the earth

salt the earth (third-person singular simple present salts the earth, present participle salting the earth, simple past and past participle salted the earth)

1. (literal) To spread salt over arable land to destroy its fertility, especially as a scorched-earth tactic of war and/or genocide.
2. (idiomatic, hyperbolic) After destroying or devastating something, to do something additional to make sure it is permanently destroyed, as a precaution or out of spite.

• Not to be confused with, and very different in meaning from, salt of the earth.