noun
Usage: sometimes capitalized V & usually capitalized X
1. : any of various viruses that are imperfectly identified
2. or virus x disease : a disease caused by a virus X
noun
Usage: sometimes capitalized V & usually capitalized X
1. : any of various viruses that are imperfectly identified
2. or virus x disease : a disease caused by a virus X
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012