It's a bit of a playful and informal way to express enthusiasm or admiration.
Here are some examples of how you might use it:
* "That new restaurant is well wicked! I'm definitely going back."
* "Your new haircut is well wicked!"
* "The band was well wicked last night."
Essentially, it's similar to saying "that's awesome" or "that's amazing" in a more casual and regional dialect.