narbule
n. A small bump or protrusion, usually (but not always) round.
"Wipe your feet on the gray narbulated mat."
Or, "It drives me nuts when these &*$%#% narbules break off because you can't replace them and the stupid thing never sits flat again."
Or, "It drives me nuts when these &*$%#% narbules break off because you can't replace them and the stupid thing never sits flat again."