aconite Syllabification: (ac·o·nite)Pronunciation: /ˈakəˌnīt/Definition of aconite noun a poisonous plant of the buttercup family, which bears hooded pink or purple flowers. It is native to temperate regions of the northern hemisphere. Genus Aconitum, family Ranunculaceae: many species, including monkshood and wolfsbane an extract of aconite, used as a poison or in medicinal preparations. Origin: mid 16th century: via French and Latin from Greek akonitonaconite in other Oxford dictionaries Definition of aconite in the British & World English dictionary