Avellan is a type of nut that is commonly found in the northern hemisphere. This nut is also known as a hazelnut, due to its similarity in taste and appearance. It is a popular ingredient in many recipes, including cakes, cookies, and chocolates. However, if you are looking for more synonyms for avellan, you can use the terms cobnut or filbert. These two words also refer to the same type of nut. Furthermore, other similar types of nuts that can be used as substitutes for avellan include pecans and walnuts, which are also rich in flavor and nutrients.