virus x

noun

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

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!