hazelnut hazelnut /ˈheɪzəlˌnət/

noun

1. Nut of any of several trees of the genus Corylus  ( cob , cobnut , filbert , hazelnut )
   nut of any of several trees of the genus Corylus
    Hazelnuts are a key ingredient in Nutella
   Hazelnuts are a key ingredient in Nutella
   
   
2. Any of several shrubs or small trees of the genus Corylus bearing edible nuts enclosed in a leafy husk  ( hazel , hazelnut , hazelnut tree )
   any of several shrubs or small trees of the genus Corylus bearing edible nuts enclosed in a leafy husk