cobnut

[kob-nuht] /ˈkɒbˌnʌt/
noun
1.
the nut of certain cultivated varieties of hazel, Corylus avellana grandis.
2.
a tree bearing such nuts.
Origin
1400-50; late Middle English cobylle nutt. See cobble1, nut
British Dictionary definitions for cobnut

cobnut

/ˈkɒbˌnʌt/
noun
1.
other names for a hazelnut
Word Origin
C16: from earlier cobylle nut; see cobble1, nut