bottle booger
The dried up bit of substance crusting at the opening of a bottle that impedes the flow and sometime ends up in your dispensed portion. Often found on mustard, ketchup, and lotion. (See also lotion booger.)
Cindy: "Mom, Danny just flicked a bottle booger at me."
Danny: "See, it's just ketchup."
Mom: "Danny, stop picking bottle boogers and eating them!"
Danny: "See, it's just ketchup."
Mom: "Danny, stop picking bottle boogers and eating them!"