Serrano is a type of chili pepper with a moderate to hot level of spiciness. It is a popular ingredient in Mexican cuisine and is often used to add flavor and heat to dishes. However, there are several synonyms for Serrano that you can use if you can't find it in the supermarket. Some of the alternative names for this chili pepper include green chili, finger chili, chile verde, and mountain chili. These substitutes are not exactly the same as Serrano in terms of heat and flavor, but they are close enough to work well in most recipes. So, if you're looking to add some spice to your dishes, try using one of these Serrano substitutes instead.