Definition of declare war
- Congress has the power to declare war on/against other countries.
- The state has declared war on illiteracy.
: to make known formally, officially, or explicitly
: to make known as a determination
: to make clear
: a state of usually open and declared armed hostile conflict between states or nations
: a period of such armed conflict
: state of war
: to be in active or vigorous conflict
: to engage in warfare
: worst, overcome
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