An idiolect is a language the linguistic (i. e. syntactic, phonological, referential, etc.) properties of which can be exhaustively specified in terms of the intrinsic properties of some single individual, the person whose idiolect it is. The force of “intrinsic” is to exclude essential reference to features of the person’s wider environment, and in particular to their linguistic community. (Stanford Encyclopedia of Philosophy)
Variety of a language used by a group of speakers within a particular speech community. Every individual speaks a variety of his language, termed an idiolect. (Source)
A dialect is a version of a language spoken by a group of people. An idiolect is much smaller — it’s the way a particular person speaks, at a specific time, as distinct from others. This word is mainly used by linguists when discussing differences in speech from one person to another. Like your fingerprint, your idiolect is unique. It’s kind of like a micro-dialect. (Source)
William Archibald Spooner (22 July 1844 – 29 August 1930) was a long-serving Oxford don, notable for absent-mindedness, and supposedly liable to mix up the syllables in a spoken phrase, with unintentionally comic effect. Such phrases became known as spoonerisms, and are often used humorously. Many spoonerisms have been invented and attributed to Spooner. (Source: Wikipedia)
A spoonerism is an error in speech in which corresponding consonants, vowels, or morphemes are switched (see Metathesis) between two words in a phrase. These are named after the Oxford don and ordained minister William Archibald Spooner, who was famous for doing this.
An example is saying "The Lord is a shoving leopard" instead of "The Lord is a loving shepherd." While spoonerisms are commonly heard as slips of the tongue, and getting one's words in a tangle, they can also be used intentionally as a play on words. (Source: Wikipedia)
Key to the distinction between an idiolect and a social language is the fact that the same natural language, L, can be picked out in either of two ways: L as the language with specified linguistic (semantic, syntactic, phonological, etc.) properties, or L as the language possessed (spoken, etc.) by a specific individual or population. French, for example, is the language containing an adjective, rouge, that refers to the color red and in its spoken form begins with a voiced uvular fricative, etc. But French is also the first language of most residents of France, the lingua franca of Côte d’Ivoire, the medium in which Simone de Beauvoir wrote, spoke, and thought, etc. (Stanford Encyclopedia of Philosophy)
We gain overt prestige when we're looking towards the dominant culture.
We gain covert prestige when we're looking towards a subgroup or subversive culture.
Covert - ethnolectal varieties of Australian English eg Greek English, Chinese English.
Covert - Surfing slang, BAA, slang Vocal Fry. It verges on jargon. Occupational jargon as a marker of groups.
Lawyers' jargon/legalese - is it covert or overt? It uses standard Australian English (overt) as a marker, plus the legal jargon for covert prestige. It's like a hyperstandard (so specialised that it's signifying being a member of a group.)
LGBT linguistics (Wikipedia)
A brief history of Polari: The curious afterlife of the dead language for gay people
From closet talk to PC terminology: Gay speech and the politics of visibility
Lavender language, the queer way to speak
The secret language that broke taboos
Language and sexuality
How Rupaul's drag race fuelled pop culture's dominant slang engine
Beyond lisping: Code switching and gay speech styles
Polari, a vibrant language borne out of prejudice
What it means to 'sound gay'
Speaking in queer tongues: Globalisation and gay language