Javanais (French pronunciation: [ʒavanɛ]) is a type of French slang where the extra syllable ⟨av⟩ is infixed inside a word after every consonant that is followed by a vowel, in order to render it incomprehensible. Some common examples are gros ([ɡʁo], "fat") which becomes gravos ([ɡʁavo]); bonjour ([bɔ̃ʒuʁ], "hello"'), which becomes bavonjavour ([bavɔ̃ʒavuʁ]); and pénible ([penibl], "annoying"), becomes pavénaviblave ([pavenaviblav]). Paris ([paʁi]) becomes Pavaravis ([pavaʁavi]).^[1]

You can help expand this article with text translated from the corresponding article in French. (January 2016) Click [show] for important translation instructions. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 6,158 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing French Wikipedia article at [[:fr:Javanais (argot)]]; see its history for attribution. You should also add the template {{Translated|fr|Javanais (argot)}} to the talk page. For more guidance, see Wikipedia:Translation.

Javanais is determined by the production rule: CV → CavV. There are also many variations that can be made upon the same pattern such as: CabV, CalV, CanV, etc.

In French the word Javanais is also used to refer to the Javanese language.

Around 1957, Boris Vian wrote a song La Java Javanaise. The lyrics are a didactical method to learn the javanais. Each verse is firstly articulated in regular French, then translated in slang. As the title suggests, the song is a Java, a Parisian dance craze. In 1962, Serge Gainsbourg wrote and sang a song called La Javanaise, a pun playing on Javanese dancing and the javanais style of speaking. The song heavily employs unaltered French words that naturally have an ⟨av⟩ sequence; thus the lyrics resemble the word game of javanais.

It's also possible to substitute other sounds in place of av, at and ab being the most popular. It works well in English as well as French. For example, the sentence: Today I decided to order some nice chocolates. Could be: Tabodabay abi dabecabidabed tabo abordaber sabome chabocabolabates. The language is best spoken very fast to throw off listeners and care must be used when answering simple questions with yes/no. It's usually best to come up with code words for yes/no such that those listening cannot catch on to the trick.

• Louchebem – a form of French slang similar to Pig Latin, originally called Largonji
• Verlan – the inversion of syllables in a French word
• Ubbi dubbi
• Jerigonza