What does "brokeback" mean?

The earliest record of brokeback jokes can be found in ancient Egyptian murals around 4000 BC, which describe the dialogue between two men. From then on, "brokeback" specifically refers to gay men.

Brokeback is a dirty word. Broken back means broken, not "broken", nor does back mean "back". It means that if you go further down, you don't have to say anything. After hundreds of years of scouring, the original meaning of the word is no longer important.

Brokeback: American slang, especially for gay men, usually referring to gay men among cowboys.