Louchébem or loucherbem is Parisian and Lyonnaise butchers' (French boucher) slang, similar to Pig Latin and Verlan. It originated in the mid-19th century. Each word is transformed by moving the first consonant to the end; and suffixes such as -ème, -ji, -oc, -muche are added at the end; the letter "L" is placed at the beginning of the new word. Note that spelling often becomes phoneticised.
Some words from Louchébem, most notably "loufoque" have become common and moved into everyday slang.
There is another French argot called largonji, which differs from louchébem only in the suffix that is added (-i instead of -em); the term is derived from jargon.[1]