ras·bo·ra (r?z-bôr??)n. Any of various tropical often brightly colored cyprinid fishes of the genus Rasbora and related genera, including many species kept in home aquariums.[New Latin Rasbora, genus name, from a native word in the East Indies.]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.rasbora (ræz?b??r?) n (Animals) any of the small cyprinid fishes constituting the genus Rasbora of tropical Asia and East Africa. Many species are brightly coloured and are popular aquarium fishes[from New Latin, from an East Indian language]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ras?bo?ra (ræz?b?r ?, -?bo?r ?, ?ræz b?r ?) n., pl. -ras. any of several freshwater minnows of the genus Rasbora, of SE Asia, esp. the silvery R.heteromorpha, popular in home aquariums. [1930?35;