" declare war "

 [ "Declaration of War" ]

1: When you set the lock screen on your school computer to chocolate milk but the person who uses the computer in the period after you sets it to regular milk.

  * e.g.,  ... "I didn't want it to have to come to this, but your heinous acts have left me no choice. What you have presented me is a Declaration of War." 

 [ "declaration of war" ]

1: once again there's a threat to our world - a rebel against peace! His name: EREN JAEGER

  * e.g.,  ... this is a declaration of war 🔪 

 [ "Declare War on the North Pole Day" ]

1: A day for naughty kids to arm themselves with Nerf guns, marking their futile declaration of war against Santa and the North Pole. Always occurs on December 26th.

  * e.g.,  ... Declare War on the North Pole Day 2022 

 [ "I declare a thumb war" ]

1: I declare a thumb war is the phrase used when 2 people decide to have their thumbs go to war.

  * e.g.,  ... 1,2,3,4, I declare a thumb war. 5,6,7,8, try to keep your thumb straight.