ray humor

It's used to describe something incredibly unfunny (typically a joke, hence 'humor'). Stemming from the latin word 'radium' (which translates into ray), the joke symbolizes and projects the same natural radioactivity as radium. This radioactivity represents how repelling the unfunny joke was.

a joke that was said which was very unfunny. ray stems from the latin word radium which the radioactive metal. the joke was so unfunny that the joke produces radioactivity similar to radium.