What is the meaning of Yard_sale?

A sale of used household goods held on the seller's own premises.

The state that the participant (skier, snowboarder, skateboarder, cyclist, etc.) is in after a nasty crash, whereupon they and their equipment is laid out across the ground like pieces of a yard sale.

(Through extending the traditional sports definition,) a colorful way of expressing a notable fall during a sports activity, like trail running.