Alternatively, if you asked me "What is red?" I could point to a stop sign, then to someone wearing a red shirt, and a traffic light that happens to be red, and blood from where I accidentally cut myself, and a red business card, and then I could call up a color wheel on my computer and move the cursor to the red area. This would probably be sufficient,

Ah, so *that's* what "red" is! Man, that has stumped me for SO long. It all makes sense now! Red is the set: {some stop sign, some guy, some traffic light, some blood on Eliezer_Yudkowsky's body, a business card, and a cursor on a portion of Eliezer_Yudkowsky's screen}

But when would I ever need to use that?