Ulysses A character usually considered to be fictional. Probably based on some real person(s). Someone who takes a series of usually pointless quests. Also an (in)famous book with a long stream of consciousness section.
Un- A negating prefix.
Undine A mythical usually female beast. One of the words that's surprisingly fun to say. Try it.
Unique Something that only one of or a very few exist.
Universe A term used to describe the area of everything we think we know about.
UNIX Name of a computer operating system. Various vendors.
US Farm Report TV Show. Ostensibly a news program for the farmer or agricultural producer. In practice, grossly biased, as much opinion as fact.
Uvula The little hangy thing back by your throat in your mouth.