1. Boom-Boom 18 thumbs up buy boom-boom mugs, tshirts and magnets A display between two people to show that some act of genious/awesomeness has just happened. This is said verbally between the two persons. They can also clench a fist and knuckle tap each other whilst saying it for extra affect! It can also be used when two people say the same thing at the same time. Vixter- "Iv just had an aweso..