Combining words that generally (Sometimes) are around the same thing. You could want avidly to say something like cool and fantastic and awesome, but saying three words, you think, is going to far, so you use the magical word combination* and Aha! Coolfantawesome! Two cool people found this out one day** and decided to share it with the world, a.k.a. Urban Dictionary. This also can be used to express uncertainty. For instance, epiciafailwin.

* Not actually Magical. I wish.
** We weren't the first people. Again, I wish.

When you eat dirt for the first time and leave your family to build a shack in the woods