What does chlamydia mean?
Chlamydia is the name of a very common sexually transmitted infection caused by the bacterium Chlamydia trachomatis, as well as, more broadly, any member of the bacterial genus Chlamydia. In everyday use the word nearly always denotes the STI, which spreads through sexual contact and is notable for being frequently asymptomatic — many carriers experience no symptoms at all, which allows the infection to pass unnoticed between partners. When symptoms do occur they may include discharge or burning urination. Left untreated, chlamydia can cause serious complications such as pelvic inflammatory disease, ectopic pregnancy, and infertility, making regular screening important for sexually active people. Fortunately, the infection responds well to antibiotics when detected. The word derives ultimately from the Greek chlamys, meaning a short cloak, an allusion to the way the bacteria appear to mantle the nucleus of the cells they infect. It appears chiefly in medical, scientific, and public-health contexts.
A very common sexually transmitted infection caused by the bacterium Chlamydia trachomatis, typically spread through sexual contact and often producing no symptoms.
"He was surprised when a routine screening revealed chlamydia, since he had felt perfectly healthy."
Usually treated as an uncountable noun referring to the infection; the plural forms are mainly found in scientific contexts.
Any of various small gram-negative bacteria of the genus Chlamydia, obligate intracellular parasites that cause diseases including trachoma, psittacosis, and lymphogranuloma venereum.
"The genus Chlamydia includes species responsible for both human and animal disease."
This sense is restricted to microbiological and veterinary contexts.
In general usage, chlamydia functions as a mass noun with no plural. The Latinized plural chlamydiae appears mainly in scientific writing when referring to individual organisms or instances of infection.
"Microbiologists studied several strains of chlamydiae isolated from different patients."
The name literally means 'cloak' in Greek — early researchers thought the bacterium looked like a mantle draped around the cell's nucleus.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of chlamydia
The word chlamydia comes from New Latin, coined from the Greek khlamys (genitive khlamydos), meaning a short, sleeveless cloak worn by ancient Greeks. Scientists chose this name because the bacteria form inclusions within infected cells that were thought to resemble a cloak draped around the nucleus. The same Greek root gives us the word chlamys itself and related terms such as chlamydate in zoology.
How chlamydia is actually used
Primarily used in medical and public-health registers. In everyday speech, 'chlamydia' almost always refers to the sexually transmitted infection rather than the bacterial genus generally. It functions as both a mass noun ('she had chlamydia') and, less commonly, takes plural forms in scientific writing.
Easily confused with chlamydia
A chlamys is an ancient Greek short cloak worn draped over the shoulder, whereas chlamydia is a sexually transmitted bacterial infection.