Informal language consisting of words and expressions that are not considered appropriate for formal occasions; often vituperative or vulgar
Very informal language usage that often serves to promote a feeling of group membership. It is not usually accepted in formal speech or writing and includes expressions that may be impolite or taboo in conventional communication.
Forms of slang develop among particular groups, for example soldiers, teenagers, and criminals, and are often extended into more general use because social conditions make them fashionable or people have grown accustomed to using them. Some types of slang are highly transient; others may last across generations and gain currency in the standard language.
Because slang is often vivid, suggestive, and linked with subjects such as defecation, urination, sex, blasphemy, drink, and drugs, many people find it offensive. It is, however, pervasive in its influence.

Jezik pariske ulice i polusveta; lopovski, mangupski, šatrovački govor; govor ljudi jedne klase ili jednog zanata.
Sleng, dopuna običnog govornog jezika.

Naročiti govor jednog staleža (sportski, ribarski, studentski, vojnički, lovački, glumački, šatrovački itd.); vulgarne reči i izrazi londonske ulice.

1 > Pokvaren (ili nerazumljiv, pogrešan) govor; naročit govor, poseban govor nekog društvenog reda; osobenost jednog govora;
2 > Sitno, kao čiodina glava, hijacintu slično kamenje žute i ljubičaste boje (upotrebljava se za ukras). (fr.)