acanthus Syllabification: (a·can·thus)Pronunciation: /əˈkanTHəs/Definition of acanthus noun 1a herbaceous plant or shrub with bold flower spikes and spiny decorative leaves, native to Mediterranean regions. [via Latin from Greek akanthos, from akantha 'thorn', from akē 'sharp point']Genus Acanthus, family Acanthaceae: many species 2 Architecture a conventionalized representation of an acanthus leaf, used especially as a decoration for Corinthian column capitals. acanthus in other Oxford dictionaries Definition of acanthus in the British & World English dictionary