adj, slang ·Common ·High school level
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "infectious" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "infectious" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "infectious" with a nearby alternative so the final choice matches both meaning and reader expectation.
Check whether "infectious" is acting as adj, slang in your sentence. A definition is only useful when the grammar matches the way the word is being used.
Compare it with "infective" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Before publishing a sentence with "infectious", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
"Cancer is usually not infectious."
"Despite feeling better, the patient is still infectious."
"infectious smile"
"Pop music is more infectious than elevator music."
"The infectious case was isolated from other patients."
Caused by an agent that enters the host's body (such as a bacterium, virus, parasite, or prion); often, also, transmitted among hosts via any of various routes (for example, contact, droplet-borne, airborne, waterborne, foodborne, fomite-borne, or bloodborne).
Common synonyms include: infective, catching, communicable, comparative forms of pathogenic, contagious, contagious.
The infectious case was isolated from other patients.
Pronounced /ɪnˈfɛk.ʃəs/.
Borrowed from New Latin īnfectiōsus. By surface analysis, infect + -ious.