The Spanish word 'nogada' meaning 'walnut sauce' comes from combining the Spanish word 'nuez' (meaning 'nut' or 'walnut') with the suffix '-ada', which indicates a product or result. The word 'nuez' itself comes from the Latin word 'nux', which also meant 'nut' or 'walnut'. The transformation from 'nuez' to 'nog-' in 'nogada' reflects a common phonetic change when forming derivatives in Spanish.

A simpler and more common related Spanish word is 'nuez', which simply means 'nut' or 'walnut'. While 'nuez' refers to the nut itself, 'nogada' specifically refers to a sauce made from walnuts, most famously used in the Mexican dish 'chiles en nogada'. Another related word is 'nogal', meaning 'walnut tree'.

While not immediately obvious, the English word 'nut' is actually not related to the Spanish 'nogada'. However, English has borrowed some related words from the same Latin root 'nux', such as 'nucleus' (originally meaning the kernel of a nut) and 'nuclear'. The connection makes sense when you think of a nucleus as the central 'kernel' or core of something, just like the edible center of a nut.