What does block mean as an insult?

As an insult, "block" typically refers to someone perceived as dull, uninteresting, or lacking intelligence. It suggests that the person is unable to engage meaningfully in conversation or thought, often implying they are a hindrance to social interaction. This term can also evoke the image of a "blockhead," denoting stubbornness or ignorance. Overall, it's a derogatory way to dismiss someone's value or contributions.