What does lie thee down oddity?

"Lie thee down, oddity" is a phrase from Shakespeare's play Henry IV, Part 1. It is spoken by Prince Hal to Falstaff after Falstaff has been defeated in a fight. The phrase is meant to be humorous, as it is a play on words. "Lie thee down" is a normal phrase meaning to go to bed, but "oddity" is an unusual word that is often used to describe someone who is strange or eccentric. In this case, Hal is calling Falstaff an oddity because of his unusual behavior.