Pepperoni is a spicy red sausage sliced onto pizza. Pepperoni pizza, slices of pepperoni, extra pepperoni.
It is American, not Italian, and asking for it in Italy gets you peppers — the Italian peperoni means bell peppers. It is the commonest pizza topping in the United States by a wide margin. Note the single p in the Italian and the double in the English.
1nounpepperoniA spicy red sausage sliced onto pizza.
“I'll have a large pizza with pepperoni and mushrooms, please.”
pepperoni is a sausage.
From Italian peperoni, bell peppers, the plural of peperone. The sausage is an American invention.
Italian
peperoni — bell peppers
English, today
pepperoni
Built from
Italian peperoni (“bell peppers”), the plural of peperone (“bell pepper”).
Etymology from Wiktionary, CC BY-SA