1. To instigate or initiate war against some other country or group of people. Under the rule of its new dictator, the country has begun waging war on its neighbors in an attempt to consolidate power. A severe depletion of resources led several tribes in the region to wage war for many years.

2. To attempt to eliminate, destroy, or overpower someone, something, or some group. The new president vowed to wage war on corruption in Washington. The extremist wing of the political party has been waging war on any and all groups that disagree with their opinion in any capacity.