The Plural of Virus: Here’s What It Is and How to Use It

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The Plural of Virus: Here’s What It Is and How to Use It

Here is a brief explanation of how to use the word virus and the plural form of the word. Let’s go over the meaning of the noun virus, its plural form, the history and origin of the word, synonyms, examples of the word used in a sentence, and some more FAQ on the word virus as it relates to grammar. Next time you go to use the word virus you will be an expert. 

What Is the Definition of the Word Virus

The word virus means:

  • Any of a large group of submicroscopic infectious agents that are usually regarded as nonliving extremely complex molecules, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that cause various important diseases in humans, animals, and plants
  • A disease or illness caused by a virus
  • The causative agent of an infectious disease
  • Something that poisons the mind or soul
  • The force of this virus of prejudice — V. S. Waters
  • A computer virus that is usually disguised as an innocuous program or file, that often produces copies of itself and inserts them into other programs, and that when run usually performs a malicious action (such as destroying data or damaging software)

What Is the Correct Plural of Virus

Because the root language of the word is classical Latin, we have to first look at the gender of the word to see what the correct plural would be. The Latin word is a neutral/neuter noun so the Latin plural is vira. This follows the same rule seen with datum becoming data when it goes into its plural form according to Latin grammar and Latin dictionaries. In Latin virus has a few different endings after the root “vir” as it is a second declension noun: the genitive case virii, the dative and ablative case viro, and the nominative, accusative, and vocative “virus.” This noun ending indicates the nonexistence of plural forms except in special circumstances in neo-Latin. There are also cognates in Sanskrit and Ancient Greek.

Just like it is in other cases of English words derived from Latin nouns, there is also a more modern and in this case, more commonly used plural form. In English, we typically want to assume the English plural form of a word ends in s or es. Virus can become plural this way and is 100% grammatically correct when spelled “viruses”. 

The History and Origin of the Word

When we go back and look for the origin of the word virus we can see that it was used all the back in 1599. It was used in a different way than we use it today, it was used to describe venom. 

It comes from the Middle English language, it’s original definition was “pus, slime, discharge from a sore, semen”. It was originated, however, from the Latin root word vīrus (neuter) “venom, poisonous fluid, slimy liquid, acrid element in a substance, secretion with medical or magical properties”. 

Synonyms of the Word Virus in an English Dictionary

  • Ailment – mild sickness
  • Disease – ailment, affliction
  • Germ – microscopic organism, often causing illness
  • Illness – disease, bad health
  • Infection – contamination 
  • Microbe – bacteria
  • Microoganism – germ
  • Pathogen – microbe, bacteria, virus
  • Sickness – ill or abnormal condition

Examples of the Word in Context


Now you are an expert on all things related to the word virus. Next time you need to write the word virus, you will be well prepared for everything you need to know what it is and how to do it efficiently.