a·can·thus (?-k?n?th?s)n. pl. a·can·thus·es or a·can·thi (-th??) 1. Any of various perennial herbs or small shrubs of the genus Acanthus, native to the Mediterranean and having pinnately lobed basal leaves with spiny margins and showy spikes of white or purplish flowers.2. Architecture A design patterned after the leaves of one of these plants, used especially on the capitals of Corinthian columns.[New Latin Acanthus, genus name, from Greek akanthos, thorn plant, from akantha, thorn.]a·can?thine (-th?n, -th?n) adj.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.acanthus (??kæn??s) (??kæn?) or acanthn, pl -thuses or -thi (-?a?) 1. (Plants) any shrub or herbaceous plant of the genus Acanthus, native to the Mediterranean region but widely cultivated as ornamental plants, having large spiny leaves and spikes of white or purplish flowers: family Acanthaceae. See also bear’s-breech2. (Architecture) a carved ornament based on the leaves of the acanthus plant, esp as used on the capital of a Corinthian column[C17: New Latin, from Greek akanthos, from akantha thorn, spine]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014a?can?thus (??kæn ??s) n., pl. -thus?es, -thi (-?a?) 1. any of several plants of the genus Acanthus, of the Mediterranean region, having spiny or toothed leaves and showy white or purplish flowers. 2. an architectural ornament, as on a Corinthian capital, resembling the leaves of this plant. [1610?20;