To look something up on wikipedia. Usually used in the command form. Derived from a simplification of "look it up!" and "wikipedia" Also sounds much better than, "google it!"
Can be problematic when assuming wikipedia is the end all be all of knowledge.
Can also be used to refer to wiki how.
"You don't believe me that there's such a thing as flying fish??? Wiki up! They're totally in the arctic!"
"I don't know how to make a highball, wiki up!"