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 (ŏn-kôr′nə-vī′rəs, ŏng-)
Any of a group of viruses that contain single-stranded RNA and cause cancers in birds and mammals.

[Greek onkos, mass, tumor; see oncology + RNA + virus.]
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.


(Biology) any retrovirus which causes tumours
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
p-Lapachone, an inhibitor of oncornavirus reverse transcriptase and eukaryotic DNA polymerase-a.
La leucosis bovina (LB), conocida tambien como leucosis viral bovina (LVB), es una enfermedad neoplasica viral producida por un oncornavirus tipo C de la familia retroviridae, que ocurre con cambios en el contaje celular (linfocitosis o linfopenia persistente) y con la formacion o no de nodulos neoplasicos distribuidos de acuerdo a las variadas formas (Timica, Multicentrica, Juvenil y Cutanea) referidas en la literatura [3, 6-10, 12-16, 24, 27, 31, 38].
These viruses are supposed to lie dormant but there is nothing to stop them reactivating in a manner similar to the well known RNA oncogenic viruses (Oncornavirus) or the DNA oncogenic viruses (both inducers of leukemia, sarcomas, carcinomas, gliomas).