Language is one of humanity’s greatest inventions. It allows us to communicate ideas, tell stories, express emotions, preserve history and shape cultures. Yet language is never static. It constantly evolves, adapting to new technologies, new generations, new fashions and changing societies. One of the clearest examples of this evolution is slang—the colourful, informal vocabulary that gives every era and every community its own distinctive voice.

Ironically, while millions of people use the word slang every day, no one can say with certainty where the word itself came from.

Unlike most common English words, whose ancestry can be traced through centuries of written records into Old English, Latin, Greek or French, the origin of slang remains one of the great unsolved mysteries of historical linguistics. It is fitting, perhaps, that a word describing informal, ever-changing language should itself refuse to reveal its true identity.

A Word Without Parents

The earliest known appearance of the word slang dates from the middle of the eighteenth century, around the 1750s. By that time it was already being used to describe the colourful speech of London’s streets—particularly the language of thieves, beggars, actors, soldiers and market traders.

What puzzles linguists is that the word seems to appear almost without warning.

Normally, historians of language can follow a word backwards through older spellings and earlier forms. They may discover it evolved from an Old English word, entered English through Norman French, or was borrowed from Latin or Greek. The trail may stretch back more than a thousand years.

Not so with slang.

It simply emerges in written English with no obvious ancestor. Despite centuries of research, no earlier form has ever been convincingly identified.

For this reason, the Oxford English Dictionary simply describes its origin as “uncertain.”

Theories Behind the Mystery

Although nobody knows the answer, several intriguing theories have been proposed.

The London Underworld Theory

Perhaps the most widely accepted explanation is that slang originated within the colourful underworld of eighteenth-century London.

At that time London was the largest city in Europe, home to enormous wealth but also crushing poverty. Criminal gangs, pickpockets, prostitutes, street hawkers and confidence tricksters developed secret vocabularies to communicate without outsiders understanding them.

This hidden speech was often known as cant, but some scholars believe slang may originally have referred to this same underground language before gradually broadening its meaning to include all informal speech.

The difficulty is that no document explains how or why the word itself was created.

A Lost Dialect Word

Many modern linguists favour another possibility.

England once contained hundreds of regional dialects, many of which were spoken only by ordinary working people who rarely wrote anything down. Entire vocabularies have disappeared because they were never recorded.

It is entirely possible that slang was one such dialect word.

If so, it may have existed for generations before someone eventually wrote it in a book during the eighteenth century.

Unfortunately, if its spoken origins were never documented, they may be lost forever.

Scandinavian Connections

Because English borrowed thousands of words from Old Norse during the Viking Age, some researchers have searched Scandinavian languages for clues.

Several Scandinavian words resemble slang in sound and have meanings related to “throwing,” “casting,” or “moving quickly.” One theory suggests slang words were expressions casually “thrown around” in conversation.

While attractive, the evidence remains weak. No direct linguistic connection has ever been demonstrated.

The Invented Word Theory

There is another possibility.

Perhaps slang was simply invented.

Human beings coin new words all the time. Shakespeare created hundreds of them. Modern technology has given us words like blog, podcast, emoji and selfie.

The creators of London’s colourful street language may simply have invented the word slang itself.

If so, its birth may never have been recorded.

Spoken Language Leaves Few Footprints

One reason the mystery persists is that language existed long before dictionaries.

For most of history, ordinary people neither read nor wrote. Their words lived entirely in conversation.

Unlike royal decrees, church records or legal documents, everyday speech vanished the moment it was spoken.

Many expressions undoubtedly flourished for centuries before appearing in writing.

By the time lexicographers began compiling dictionaries during the seventeenth and eighteenth centuries, countless words had already come and gone without leaving a trace.

Slang was particularly vulnerable because it belonged largely to ordinary people rather than scholars.

Why Every Society Creates Slang

If the origin of the word is mysterious, the reason slang exists is much easier to understand.

Every society invents it.

People use slang to establish identity.

Teenagers create expressions their parents do not understand.

Soldiers develop language that reflects military life.

Sailors coin words from life at sea.

Doctors, lawyers, police officers, miners, shearers and truck drivers all possess specialised vocabularies that outsiders may find confusing.

Slang creates belonging.

If you understand the language, you belong to the group.

If you do not, you remain an outsider.

Sometimes slang also serves practical purposes.

Throughout history criminals used coded speech to avoid detection.

Political dissidents developed expressions to avoid censorship.

Minority communities often created private vocabularies for protection.

One of the most fascinating examples is the development of Polari in Britain.

Used primarily by gay men before the decriminalisation of homosexuality, Polari blended Italian, Romani, Yiddish, Cockney rhyming slang, theatrical language and naval terminology into a colourful code that allowed conversations to take place in public without attracting unwanted attention.

Australia developed its own equivalents, particularly within the gay communities of Sydney and Melbourne during decades when homosexuality remained criminalised and social prejudice was widespread.

Language became both shield and badge of identity.

Slang as Rebellion

Slang also challenges authority.

Teachers dislike it.

Parents complain about it.

Editors often avoid it.

Yet every generation invents fresh expressions despite repeated attempts to discourage them.

Victorian adults complained about the slang of their children.

The children of the 1920s developed their own vocabulary.

Baby Boomers horrified their parents.

Generation X puzzled the Boomers.

Millennials baffled Generation X.

Today’s teenagers leave almost everyone else wondering what on earth they are talking about.

This cycle has repeated for centuries.

What changes are the words—not the process itself.

Australia: A Nation Built on Slang

Few countries embrace slang as enthusiastically as Australia.

From the earliest convict settlements, Australian English developed its own distinctive character.

Convicts brought London’s criminal cant.

Irish immigrants added their own expressions.

Scottish and English dialects mixed freely.

Aboriginal languages contributed hundreds of place names and numerous everyday words.

Life in the bush encouraged brevity, humour and practicality.

Australians became famous for shortening almost everything.

Afternoon became arvo.

Service station became servo.

Mosquito became mozzie.

Breakfast became brekkie.

Football became footy.

Politician became pollie.

This habit of abbreviation reflects Australia’s relaxed conversational style.

Australian slang also celebrates equality.

Calling someone “mate” suggests friendship regardless of social status.

A person who becomes too self-important risks being “cut down to size.”

Humour, irony and understatement remain central features of Australian speech.

When Slang Grows Up

One of the most remarkable aspects of slang is that today’s informal language often becomes tomorrow’s standard English.

Words once dismissed as vulgar eventually lose their shock.

Consider a few examples.

The word mob originally referred to the disorderly crowd and was itself eighteenth-century slang, shortened from the Latin phrase mobile vulgus, meaning “the fickle crowd.”

Today it is perfectly respectable.

The word bus began as an abbreviation of the Latin-derived omnibus.

Nobody considers it slang now.

Even phone was once merely a casual shortening of telephone.

Language constantly promotes yesterday’s slang into today’s dictionary.

The Words We Leave Behind

Of course, countless slang terms disappear.

Many expressions fashionable during Victorian times now sound hopelessly old-fashioned.

The same fate awaits many of today’s fashionable expressions.

Every generation believes its slang is unique.

History suggests otherwise.

Some words survive because they fill a genuine need.

Others vanish as fashions change.

Together they form an archaeological record of everyday life.

Historians can often learn as much about a society from its slang as from its official documents.

The Great Irony

Perhaps the greatest irony is this.

The word slang describes language that refuses to stay still, refuses to obey rules and constantly reinvents itself.

Yet the word itself behaves exactly the same way.

It emerged unexpectedly in eighteenth-century England.

It left almost no clues about its ancestry.

Despite more than 250 years of linguistic scholarship, nobody has managed to identify its true origins with certainty.

Perhaps that is entirely appropriate.

Some mysteries lose their charm once solved.

The history of slang reminds us that language belongs not only to kings, scholars and dictionary writers, but also to ordinary people—dockworkers, convicts, actors, soldiers, miners, market traders, factory workers, teenagers and countless others whose conversations were rarely recorded.

Their voices shaped the English language every bit as much as Shakespeare’s or Samuel Johnson’s.

Most have been forgotten.

Their words, however, continue to echo through history.

And among those words is one that still keeps linguists guessing.

Slang.

Tim Alderman ©️2026

Sources

Oxford English Dictionary. Slang (entry and etymological notes).

Jonathan Green, Green’s Dictionary of Slang.

Eric Partridge, A Dictionary of Slang and Unconventional English.

Tony Thorne, Dictionary of Contemporary Slang.

Michael Adams, Slang: The People’s Poetry.

Jonathon Green, The Vulgar Tongue: Green’s History of Slang.

David Crystal, The Stories of English.

David Crystal, The Cambridge Encyclopedia of the English Language.

Oxford Reference, entries on slang, cant and argot.

Tim Alderman ©️2026