tetracycline

noun

tet·​ra·​cy·​cline ˌte-trə-ˈsī-ˌklēn  -klən 

: a yellow crystalline broad-spectrum antibiotic C₂₂H₂₄N₂O₈ produced by streptomyces or synthetically

also : any of several chemically related antibiotics (such as doxycycline)

Did you know?

Most chemical names are made up of two or more Greek and Latin roots strung together. Thus, tetracycline, with its cycl- root from the Greek word for "circle", means "four-ringed"—that is, "consisting of four fused hydrocarbon rings". Antibiotics work against bacteria and other tiny organisms (but not viruses); tetracycline, which comes from a kind of soil bacteria, is one of the most used of the antibiotics. "Broad-spectrum" antibiotics work well on numerous organisms; thus, tetracycline has proved effective against acne, chlamydia, cholera, rickets, and various lung and eye infections, among many other conditions.

Examples of tetracycline in a Sentence

Recent Examples on the Web

Being in the sun while on tetracycline antibiotics can also cause skin reactions, including burning, tingling, swelling, hives, and nail separation from the nail bed.5 Other side effects: Stomach upset6 3. —Megan Nunn, Verywell Health, 27 Aug. 2025

The study’s authors showed that common antibiotics, such as amoxicillin and tetracycline, stuck to microplastics—and that, the older the microplastics were, the more readily the antibiotics attached to them. —Marta Zaraska, Scientific American, 26 Aug. 2025

Other risk factors include taking certain medications such as tetracycline, excessive vitamin A, tretinoin, steroids and growth hormone. —Danielle Wilhour, The Conversation, 28 May 2025

Fortunately, this strain was still susceptible to the antibiotic tetracycline, one of the drugs of choice for cholera. —Beth Mole, ArsTechnica, 11 Apr. 2025

Word History

Etymology

International Scientific Vocabulary tetracyclic having four fused hydrocarbon rings + -ine entry 2

First Known Use

1952, in the meaning defined above

Rhymes for tetracycline

• anthracycline
• doxycycline
• minocycline
• chlortetracycline
• oxytetracycline

Kids Definition

tetracycline

noun

tet·​ra·​cy·​cline ˌte-trə-ˈsī-ˌklēn 

: a yellow crystalline antibiotic produced by a soil bacterium or made synthetically

Medical Definition

tetracycline

noun

tet·​ra·​cy·​cline ˌte-trə-ˈsī-ˌklēn  -klən 

: a yellow crystalline broad-spectrum antibiotic that is produced by a soil actinomycete of the genus Streptomyces (S. viridifaciens) or made synthetically and that is administered chiefly in the form of its hydrochloride C₂₂H₂₄N₂O₈·HCl

also : any of several chemically related antibiotics (as doxycycline)