When a person goes to blow their nose and the tissue or snot rag that they have isnt big enough to hold all the snot thats comeing out ,can be embarassing .
When your nose is running so much and is so raw that instead of blowning your nose for the hundredth time you just stick tissues up your nose so snots not dripping out, the remainder of the tissue sticking out of your nose resembles old fashioned sheet ghosts. Hence Snot Ghosts.
My nose is so raw from blowing it so much, that I opted for snot ghosts today for some relief.
In football, when a player hits another player so hard, that the player who was hit has snot literally knocked out of his nose. More common in the winter when people tend to have colds. Sometimes called a "slobber knocker".
Wide recievers fear going over the middle, because they're afraid they'll get a snot knocker.
A insult directed to a person (you believe) to be of lower class or status. Someone for whom perhaps the swallowing of snot is challenging enough occupation alone.
"Get away from my car you snot gobbling little shit bag!"
or as an affectionate term of greeting: "Alright snot gobbler?"
A snot whistle is the whistling sound created when the nasal cavity can let only a small amount of air through the nostrils, thus creating an aerophone.
John: Is someone whistling quietly?
Bill: Nah, man. I've had a cold all week and now I have snot whistle.