tl;dr, short for "too long; didn't read", is @Reddit slang to say that some text being replied to has been ignored because of its length. In slang it can also stand for "Too lazy; didn't read". It is also used as a signifier for a summary of an online post or news article.
Contexts
- #reddit-lexicon (See: @Reddit Glossary)
- #index (See: #index)