I declare a thumb war Share definition Flag I declare a thumb war is the phrase used when 2 people decide to have their thumbs go to war. 1,2,3,4, I declare a thumb war. 5,6,7,8, try to keep your thumb straight. I declare a thumb war by Puppybcm February 11, 2023 0 0 Get merch Get the I declare a thumb war mug. Buy Now — $32.95 See more merch