The clap and other STI names through the ages

Nobody knows for certain. The word ‘clap’ for the disease was first recorded in English in the 1580s, and dictionaries say it most likely comes from French:

• ‘clapoir’, an old French word for a bubo, a swollen gland in the groin
• ‘clapier’, a rabbit burrow, which was also slang for a brothel

You may have heard other stories, such as men clapping their penis to clear the discharge, or the name coming from an Old English word for throbbing. There’s no evidence for either. The Old English word gave us the everyday verb ‘clap’, but dictionaries treat the name for the disease as a separate word.

The word Gonorrhoea comes from Greek words meaning ‘seed’ and ‘flow’, because ancient doctors mistook the discharge for semen. The name is usually credited to the Greek doctor Galen in the second century AD, and it reached English in the 1520s.

The infection itself is very old. In medieval England, what was probably Gonorrhoea was known as ‘the burning’, and from the 1500s it was often called ‘the clap’.

Syphilis swept across Europe from 1495, after an outbreak among French troops in Naples. People called it ‘the great pox’ to tell it apart from smallpox.

Every country seemed to blame another:

• Italians called it the French disease.
• The French called it the Neapolitan disease, after Naples.
• Russians called it the Polish disease, and Poles called it the German disease.
• Turks called it the Christian disease.
• In India, it was called the Portuguese disease.

The name we use today comes from a Latin poem published in 1530 by the Italian doctor and poet Girolamo Fracastoro. In it, a shepherd called Syphilus insults the sun god and is punished with the disease. The name didn’t come into general use until the early 1800s.

Many experts think Columbus’s crews brought Syphilis to Europe from the Americas. Recent studies of ancient DNA support that idea, although the debate isn’t fully settled.

Chlamydia gets its name from the Greek word ‘chlamys’, meaning a cloak. In 1907, scientists looking at infected cells under a microscope saw clusters of the bacteria draped around the nucleus like a cloak, and thought they had found a protozoan, a type of single-celled parasite. They were wrong about what it was, but the name stuck.

The same bacterium causes trachoma, an eye disease described in ancient Egypt around 1550 BCE. Genital Chlamydia, though, was only shown to be common in the 1960s.

For centuries, doctors called these infections venereal diseases, after Venus, the Roman goddess of love. The term was first used in 1527 and appears in English from the 1650s. It was later replaced by ‘sexually transmitted disease’ (STD).

Since 1999, the World Health Organization has preferred ‘sexually transmitted infection’ (STI), because many infections cause no symptoms. Other historical names include ‘the pox’, ‘the French pox’ and ‘morbus gallicus’ (the French disease) for Syphilis. Read more in “STD or STI: What’s in the name?”

The names may be old, but these infections are still common. In England in 2025, there were:

• 151,163 Chlamydia diagnoses
• 63,943 Gonorrhoea diagnoses
• 8,262 infectious Syphilis diagnoses

All three can usually be treated with antibiotics, but they often cause no symptoms, so testing is the only way to know. Left untreated, Chlamydia and Gonorrhoea can lead to infertility, and Syphilis can spread to the brain and other parts of the body.

Since August 2025, England has also offered a vaccine that helps protect against Gonorrhoea to people at higher risk, mainly gay and bisexual men. Read more in “Chlamydia vs Gonorrhoea: how do you tell them apart?”

Better2Know offers:

• Peace of Mind: a blood and urine test for Chlamydia, Gonorrhoea and Syphilis from 14 days after sex, with results in 2 days, at one of our clinics. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test.
• Full Screen: tests for 7 infections, including Chlamydia, Gonorrhoea, Syphilis and HIV, from 28 days after sex, with results in 3 days (5 days for the home test). If you test before 45 days, a negative HIV result needs a repeat test. You can also order a Full Screen home test.
• Platinum Screen: our most comprehensive STI screen. It tests for 12 infections, adding Hepatitis C, Herpes 1, Herpes 2, Trichomonas and Gardnerella to the Full Screen, from 28 days after sex, with results in 3 days. If you test before 45 days, a negative HIV result needs a repeat test.

Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

Is the clap the same as Chlamydia?

No. ‘The clap’ is slang for Gonorrhoea. Chlamydia and Gonorrhoea are different infections, although they can cause similar symptoms and you can have both at the same time.

What was Syphilis called in the past?

Syphilis has been called the great pox, the pox, the French pox and morbus gallicus, and many countries named it after their neighbours.

Is the clap still around today?

Yes. Gonorrhoea is the second most commonly diagnosed STI in England after Chlamydia. It often causes no symptoms, especially in women and in the throat or bottom, so regular testing matters.

The names we use for STIs come from Greek doctors, French slang, a Renaissance poem and a microscope mistake. What hasn’t changed is that Gonorrhoea, Syphilis and Chlamydia are still common, and they often cause no symptoms.

If you’ve had sex without a condom with a new partner, get tested. Book a Peace of Mind test at a clinic near you. Our Patient Care Team is available 24/7 on 020 7099 0955.

Not in the UK? Choose your country from the selector at the top of the page for local tests and prices.

This article originally appeared on 5 August 2022 and was last updated on 30 September 2026.

This article is general information and not a substitute for personal medical advice.

Sources

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