4. "Spice" is a variety of drugs.
We don't know much about Han Solo's smuggling career from the information provided in the films - we know he smuggles things, and that those things are probably illegal, and that a big desert slug is none too happy with his smuggling prowess, and that he would never ever be the first one to shoot another over a dispute involving smuggling. That's where the Expanded Universe of books, comics, and videogames comes in handy - filling in literally every possible corner of the Star Wars galaxy (remember that droid that Uncle Owen was gonna buy but it broke down? That was Skippy the Jedi Droid!). It turns out Han Solo was a big-time spice smuggler - but not the spice of making food taste better. Nope, it's similar to the sci-fi mind-expanding narcotic from the Dune series. That's right - spice is drugs. Which makes Han Solo a drug smuggler.
The variety of specific spice drugs runs the gamut from Giggledust (which makes everything seem funny) to Thruster Head (which caused extreme hallucinations). Han tended to smuggle the dirtier stuff for the Hutts, because he's a vaguely-menacing rogue who does whatever he needs to in order to survive and not a hyper-moral prince valiant who only shoots in self-defense.
3. "Wyrwulf" is a baby alien.
When you hear the term "wyrwulf," odds are you think it's the Star Wars equivalent of a werewolf (but spelled differently because they just haaave to be different). Except, it's totally not that. Nope, wyrwulves are six-legged wolves that are actually just baby aliens. See, once they reach puberty, they turn into a cocoon and emerge as a four-armed humanoid alien of the Codru-Ji species (that have almost no canine features, it should probably be noted because what the hell?). This all means that a fully-grown Codru-Ji's kid looks an awful lot like it's just the family dog. A reminder to Codru-Ji parents out there: don't confuse your dog with your child, unless you're cool with accidentally neutering Junior.
2. "Jizz" is a type of music.
Yes. "Jizz" is a genre of music in the Star Wars universe. Those who play Jizz are known as "Jizz-wailers." This is all real. Figran D'an and the Modal Nodes (the weird testicle-headed cantina band from A New Hope that has a name and it's Figran D'an and the Modal Nodes) play Jizz. The "doo doo doo da doo doo doo" cantina music is Jizz.
The term first appeared in the novelization of Return of the Jedi, written by James Khan, who must have had a nice laugh to himself by adding the term "jizz" into Star Wars canon as a predominant genre of music. George Lucas probably wouldn't have allowed this if he were paying attention at all, but he was pretty busy stroking his tiny beard and salivating as Ewok toy sales that year.
1. "Heyblibber" is a word that exists.
It's a type of Gungan underwater transport ship, instead of what it should mean: nothing, because 'heyblibber' is too dumb of a word to be real.