Virile and viral are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
Virile (pronounced “veer-uhl”) is an adjective. It means relating to men, or male characteristics like physical strength and procreation. Virility is a related noun.
Viral (pronounced “veye-ruhl”) is an adjective. It describes something resembling a virus or a virus’ behavior. The idiom “going viral” describes a product or idea that is shared among a lot of people in a relatively short period of time.
The following story uses both words correctly:
Virgil was hoping his company’s latest drug, Gladiator, would be a viral hit. Gladiator said it made clients virile, energetic, and ready to take on the world. It was going to be tough to stand out in an already crowded marketplace for supplements. Other companies had a higher marketing budget.