American condiment made by drying and coarsely crumbling cayenne peppers with their seeds. On tap (mostly) in pizza parlors, and of varying potency, since peppers lose their heat while aging: my mother well remembers a friend of hers "from the South" vigorously peppering her pizza (in New Haven, where Pizza was Invented--yes, really, though New York also claims it, but in the same year), expecting nothing more than a mild piquancy...she remembers ordering milk a minute later!
Note that I'm not using this in the sense of "a pepper (bell, pimento, ghost) that is red", anymore than "black pepper" refers to a purple bell pepper. Ask for a shaker of "red pepper" and this is what you get, and (mostly) a spoonful of "red pepper" is this condiment, not a chopped fresh one.