a·ya·hua·sca (??y?-wä?sk?, ä?y?-)n. A hallucinogenic brew made from the bark and stems of a tropical South American vine of the genus Banisteriopsis, especially B. caapi, mixed with other psychotropic plants, used especially in shamanistic rituals by certain Amazonian Indian peoples.[American Spanish, from Quechua, rope of the dead, narcotic : aya, corpse + huasca, rope.]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.ayahuasca (?a???w??sk?) or ayahuascon (Plants) a Brazilian plant, Banisteriopsis caapi, that has winged fruits and yields a powerful hallucinogenic alkaloid sometimes used to treat certain disorders of the central nervous system: family Malpighiaceae[C20: from Quechua]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014a?ya?huas?ca (?? y??w? sk?) n., pl. -cas. a woody South American vine, Banisteriopsis caapi, of the malpighia family, having bark that is the source of harmine, a hallucinogenic alkaloid used by Indians of the Amazon basin. [