* Stupid or slow-witted: "He's so thick, he doesn't understand simple instructions."
* Clumsy or awkward: "She's got thick fingers, so she always drops things."
* Unrefined or unsophisticated: "He's got a thick accent, which makes him sound uneducated."
* Dense or impenetrable: "The jungle was thick with vegetation, making it difficult to navigate." (This can also be used metaphorically to describe a person's understanding.)
* Heavy or cumbersome: "The book was so thick, it was hard to hold."
The specific negative connotation of "thick" depends on the context.
It's important to note that:
* "Thick" can sometimes have a positive connotation, like describing a delicious soup or a lush forest.
* The use of "thick" can be offensive, especially when referring to someone's intelligence. It's generally best to use more neutral language.