Prison slang has existed in Russia since at least the time of the first prisons, where convicted criminals were held, that is, since the 16th century. For a long time, it remained just the language of criminal elements. However, from the 20th century, prison vocabulary began to spread among the general population. This is largely due to the significant increase in the number of prisoners serving time in Soviet prisons and labour camps, such as Gulag, compared to pre-revolutionary Russia. Mass amnesties letting former prisoners back to society and the popularization of criminal romanticism by certain figures in culture also contributed to this process. 

Certainly, the cant is not only typical of people who are serving a sentence or belong to criminal groups. At present, the language is known as “Fenya”, omnipresent in the Russian language and is being used by people of all ages and with different social background. Even in the speech of politicians and officials there are plenty of jargon words, and society now considers them literary, not noticing them in everyday speech and not fully understanding their meaning.

However, interest among linguists and curious intellectuals in the specific language of prisoners has always been high. Even during the time of Imperial Russia, many scholars published works on this subject. For example, V. Dahl compared prisoners’ jargon to "criminal music" composed by thieves and swindlers of various types. 

Romani language elements are present in the vocabulary of almost all the cant languages in Europe. They are one of the few common elements, which is quite understandable, considering that Roma people are scattered across the world and some of criminals come from their community.

The existence of close, long-lasting contacts between those who use the jargon and Roma people, whose living conditions were not much different from those of wandering traders, itinerant craftsmen and others influenced the penetration of Romani words into criminal argot. Interestingly, until the middle of the last century, the Romani language was considered an artificial language, meaning it was often equated with cant.

Romani borrowings are present in Russian Fenya as well, but they are few. One of the most frequently used ones is “lave” (лавэ), which means “money” or “cash”. The first mentions of “lave” as a word from prison slang date back to the 1920s-1930s. 

In Croatia the word “lova” is associated with the Lovari Roma, the original Croatian Roma, who have been settled here since the 14th century. The Lovari were very much involved in trade, especially horses, and their trade led to their name being derived from the word "lovi". The Lovari were once known not only for their trading skills, but also for being the only Roma group that traditionally lived in solid housing units.

Another common example is “khavat'" (хавать) meaning "to eat" or “to devour” is believed to have come from the Romani expression “Me hava” which means “I eat”. It’s often used in casual or playful contexts and is particularly popular among younger generations. The word became so popular that later derived forms emerged, such as “khaval'nik” (хавальник) – mouth, “khavka” (хавка), “khavchik” (хавчик) – food.

Furthermore, “labat’” (лабать) in Russian slang means “to play a musical instrument,” especially in the context of playing with skill or in a somewhat improvised, informal way. The word comes from the Romani language as well, which is consistent with Roma people's historical connection to music, as many communities have been known for their musical traditions, particularly with instruments like violins, guitars and other string instruments.

In conclusion, the influence of the Romani language on Russian is a fascinating example of linguistic exchange, shaped by centuries of Roma community being part of Russian society. From criminal slang to colloquial expressions, many Romani words have become an integral part of the lexicon of the Russian language, often shaping the informal and street-level speech. Terms related to trade, music, food, and work have found their way into everyday language, often taking on new meanings or nuances along the way. The adoption of Romani words into Russian showcases the fluidity of language and how communities influence each other over time, enriching the vocabulary and creating a unique linguistic tapestry.