tl;dr

A) "Too long; didn't read.", meaning a post, article, or anything with words was too long, and whoever used the phrase didn't read it for that reason. B) Also used by someone who wrote a large posts/article/whatever to show a brief summary of their post as it might be too long.
On this page, you will find 30 slang terms related to tl;dr. Some of the top words include: supercalifragilisticexpealidocious, flibbertigibbet, hootnani, oro, ala kazamm, and 25 more.