(n.) The suffocating stench of horse shit on the breeze, shortly after manure has been spread or during the spring thaw when the stables make their presence olfactorily known. The term stems from the primitive mystical cult of the Great Horse in the Sky -- Sky Horse. The phenomenon of Sky Horse is particularly well known at rural colleges.
Rene: "Ah, jaysus, that smells foul. What is that?!"
Pablo: "That'll be Sky Horse coming back--it's April, you know."
Rene: "Fuck. Of course."
Diego:"Why are you inside on such a beautiful day?"
Frida:"I'm avoiding Sky Horse, man. Maybe next week."