earthnutPronunciation: /ˈəːθnʌt/Definition of earthnut noun 1a Eurasian plant of the parsley family, which has an edible roundish tuber and is found in woodland and acid pasture. Also called pignut, hognut.Conopodium majus, family Umbelliferae the almond-flavoured tuber of the earthnut. 2Britishanother term for peanut.earthnut in other Oxford dictionaries Definition of earthnut in the US English dictionary