abbr.- Totally Unnecessary Sprint
A TotallyUnnecessarySprint is best performed in public to strike a reaction out of people, most times done without warning and without the knowledge of your friends so that when they walk past the people who witness your TUS, that person lets them know their reaction; whether by facial expression or verbally.
Yo check that dude out! Sprinting in the middle of Wal-Mart!
Yeah, that's now officially known as a TUS.