Convict Slang & Flash Language — Where Australian English Begins

FLASH

Convict Shirts — Australian Slang Series

CONVICT SLANG &
FLASH LANGUAGE

The criminal cant of the First Fleet — dob in, swag, nark, fence, lurk, rort. How the flash language of 1788 became the foundation of Australian English.

Where Australian English Begins — The Flash Language

Australian English did not begin with the First Fleet's officers or its chaplain or its surgeon. It began with the convicts — and specifically with the private criminal vocabulary those convicts brought with them from the streets of London, Dublin and the English provinces. That vocabulary was called flash language, or simply the flash, and it was the first distinctively Australian vernacular.

Flash language was not slang in the casual contemporary sense. It was a functional cant — a code developed by and for the criminal underclass of 18th-century Britain, used to conduct business and conversation without being understood by magistrates, constables, or anyone else outside the community. To speak flash was to signal membership of a specific social world, to communicate information that the authorities were not meant to hear, and to mark yourself as someone who knew how things actually worked.

When the First Fleet arrived in 1788, roughly a third of its human cargo were practised speakers of this cant. They were accompanied by officers and free settlers who did not speak it — but who were about to spend years living in close proximity to people who did. The result was inevitable: the flash leaked.

From Cant To Culture — A Timeline

1788 — Arrival

The First Fleet lands at Sydney Cove. Of approximately 1,400 people on board, around 780 are convicts — the majority transported from London and the English provinces for offences ranging from petty theft to highway robbery. They bring with them a well-developed criminal cant used in the rookeries of Seven Dials, St Giles and Whitechapel.

1788–1800 — Contact & Leakage

The flash begins leaking into general colonial usage. Officers record unfamiliar terms in journals and dispatches. The cant's function as a private code is compromised by proximity — it is impossible to maintain secrecy when the same 1,000 people live in a confined settlement for a decade.

1812 — First Dictionary

James Hardy Vaux, a convict transported three times, writes the Vocabulary of the Flash Language while imprisoned at Newcastle — the first dictionary of Australian criminal cant. It documents over 300 terms and provides a snapshot of the vocabulary at its point of peak usage.

1820s–1850s — Dispersal

As the convict population disperses into the interior, the flash disperses with it. Terms enter the vocabulary of squatters, shepherds, drovers and miners. The cant loses its exclusive criminal function and becomes general colonial vernacular.

1851 — Gold Rush Acceleration

The gold rushes bring 500,000 people to Victoria and New South Wales in a decade. The colonial vocabulary — already incorporating substantial flash language — is spread rapidly through an enormous influx of new speakers, many of whom adopt local terms as markers of colonial identity.

1880s onward — Normalisation

What were once criminal terms are now simply Australian. Swag, lurk, rort, nark, fence, dob — all present in Australian English as ordinary vocabulary, their origins largely forgotten by their speakers.

The Vocabulary — Flash Terms That Survived

Swag

Noun — origin: flash language

In flash language: stolen goods; a bundle of plunder. In contemporary Australian English: a rolled bundle of bedding and personal possessions carried by a swagman — and by extension, a large quantity of something desirable (a swag of options). The word has travelled from criminal cant to romantic symbol of the itinerant Australian worker, which is a remarkable journey for a term that originally meant stolen property.

"The swagman camped beside the billabong." / "There's a whole swag of them."

Lurk

Noun — origin: flash language

In flash language: a criminal scheme or dodge; a method of making money through deception or cunning. In contemporary Australian English: a scheme, trick, or clever angle — not necessarily criminal, often admired. What's your lurk? asks about someone's angle or occupation. A good lurk is a profitable or clever arrangement. The criminal origin has been almost entirely bleached from contemporary usage.

"What's his lurk?" / "That's a good lurk if you can get it."

Rort

Noun / verb — origin: flash language

In flash language: a trick or fraud. In contemporary Australian English: a fraudulent scheme, particularly one exploiting a system or public resource — and the verb form, to rort, means to exploit such a system. Rorting the expenses, a rort as a political scandal. The word has achieved particular prominence in Australian political journalism as the standard term for the misuse of public funds or entitlements.

"The expenses rort brought down three ministers." / "They've been rorting the system for years."

Nark

Noun / verb — origin: flash language

In flash language: an informer; a police spy. In contemporary Australian English: an informer or someone who reports others to authority — and the verb, to nark, means to inform or to annoy. The word retains its negative connotations. Being called a nark is not a compliment in Australian social culture, which has a persistent anti-informer tradition running from the convict era to contemporary expressions such as don't dob.

"Don't be a nark." / "Who narked to the teacher?"

Dob (in)

Verb — origin: flash language

To inform on someone; to report someone to authority. One of the most culturally significant inheritances from flash language in contemporary Australian English. The anti-dobbing ethic — the strong social injunction against informing on others — is one of the most persistent values in Australian culture, documented from the convict era to the present. Dobbing is considered a serious social transgression in many contexts, particularly among children and in working-class culture.

"Don't dob me in." / "He dobbed on his mates."

Fence

Noun / verb — origin: flash language

In flash language: a receiver and seller of stolen goods; and the verb, to fence, means to sell stolen property through such a person. In contemporary Australian English, the word retains both meanings essentially intact, though the frequency of use has declined with the rise of more specific contemporary vocabulary. One of the flash terms that entered standard English across multiple dialects rather than remaining distinctively Australian.

"The fence moved the goods before they could be traced."

Mug

Noun — origin: flash language

In flash language: a gullible person; someone easily deceived. In contemporary Australian English: a fool; someone who can be taken advantage of. Ya mug is a common expression of mild contempt or affectionate exasperation. The word has lost most of its specifically criminal edge but retains the core meaning of someone who is easier to deceive than they should be.

"Rack off, ya mug." / "Don't be a mug — read the fine print."

The Anti-Dobbing Ethic — Flash Language As Cultural Value

The most significant legacy of flash language in contemporary Australian culture is not lexical but ethical. The convict experience produced a specific set of values around authority, loyalty, and informing — values that have proved remarkably durable across two centuries and several social revolutions.

The anti-dobbing ethic — the injunction against informing on peers to authority — is one of the most consistent threads in Australian social culture. It is present in schoolyard culture, in working-class culture, in criminal culture, and in the broader Australian suspicion of official explanations and institutional authority. Its origins are directly traceable to the convict cant: dob, nark, lag — the vocabulary of informing is rich, consistent, and negative.

This is flash language's most lasting achievement: not the specific words, many of which have faded, but the values the vocabulary encoded — values that became, over two centuries, simply Australian.