What does J K mean?

"J K" typically stands for "Just Kidding". It's a common internet slang used to indicate that the previous statement was meant to be humorous or sarcastic, and not to be taken seriously.

However, without context, it's impossible to be certain. It could also stand for:

* J.K. Rowling, the author of the Harry Potter series

* John Keats, a famous English Romantic poet

* Initialism for a name or organization

To understand what "J K" means in a specific context, you need more information about the situation in which it was used.