What does measles mean?
Measles is an acute viral infection caused by the measles virus. Its familiar symptoms include high fever, a cough or runny nose, red eyes, and a spreading red rash, and it is extremely easy to transmit. Serious complications can include pneumonia, encephalitis, and hearing loss, making vaccination and prompt treatment important. In English, the noun retains a historical plural form and is normally used without an added plural ending; both plural and singular agreement occur, depending on style and context. The medical term rubeola is another name for the disease, while German measles refers to the unrelated infection rubella. Measles also has a rare, dated transitive verb meaning "to infect with measles." Although the disease is preventable through vaccination and has been eliminated from many regions, it continues to cause outbreaks wherever vaccination coverage is inadequate. Understanding both the word and the distinction from German measles is therefore important in medical, historical, and public-health contexts.
An acute, highly contagious viral infection caused by the measles virus, characterized by fever, respiratory symptoms, and a widespread red rash.
"The hospital isolated the patient after measles was confirmed."
The noun is conventionally plural in form, though both singular and plural agreement are used in modern medical and public-health prose.
To infect someone with measles.
"The old medical record stated that the child had been measled during an earlier outbreak."
Rare and dated; uncommon in contemporary English.
The noun normally retains a plural form and takes no additional plural ending. Both plural and singular agreement are attested.
"The measles are spreading rapidly through the community."
Measles is one of the most contagious diseases known—and vaccination can prevent it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does measles come from?
The English word descends through Middle English meseles, a plural form that was retained when measles became the standard spelling of the plural. It belongs to a Germanic family of cognates that includes German Masern, Dutch maseren, and Danish mælinger. The historical plural reflects the older conception of the disease as a collection of numerous spots or eruptions.
Related word forms
How measles is actually used
The noun is conventionally plural in form, although singular agreement such as "measles is" is also common in medical and public-health writing. The verb meaning "to infect with measles" is rare and now dated.
Easily confused with measles
German measles is rubella, a different viral infection, whereas measles is the more severe disease caused by the measles virus.