1) Underdog is the name of a race track which can be found at the Torn City Raceway.
Unicorn
1) noun Slang; a piece of weaponry or armor which has high stats, and is therefore rare.
Upkeep
1) noun This refers to the fees charged for the upkeep of your property. When upkeep is due to be paid on a property, you cannot hire staff or make any customizations. You also cannot trade the property or list it on any markets. Failure to pay upkeep may also reduce the happiness it provides.
Uptown
1) Uptown is the name of a race track which can be found at the Torn City Raceway.
URT
1) Initialism; Ultimate Racing Tournament, an annual racing competition run by Sugarvalves in the summer and winter, where the grand prize is a Bugatti Veyron.