Nut (food)

A nut is a fruit consisting of a hard or tough nutshell protecting a kernel that usually is edible. In general usage and in a culinary sense, many dry seeds are called nuts. In a botanical context, "nut" implies that the shell does not open to release the seed (indehiscent). Most seeds come from fruits that naturally free themselves from the shell, but this is not the case in nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. The general and original use of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pistachios, and Brazil nuts, are not 'nuts' in a botanical sense. Common use of the term 'nut' often refers to any hard-walled, edible kernel. Nuts are an energy-dense and nutrient-rich food source.