Webster's Revised Unabridged Dictionary defines the term slang as: n 1: informal language consisting of words and expressions that are not considered appropriate for formal occasions; often or vulgar; 2: a characteristic language of a particular group (as among thieves); Slang is believed to have originated from terms used by a certain exclusive group in society. Most slang in England was derived from a criminal lingo, called the English Criminal Cant, which is still in use to this day in parts of East London. But in today's world, words which have meanings deeply rooted in slang usage are used by the majority in everyday talk.
These words were almost always thought of as crude, vulgar, and too disrespectful to a woman's ears. But today they are wholesome, family words used to add zest or flavor to an otherwise boring English. Some examples include "sucker", "jerk", "babe", "chick", "dame", "gum-shoe", "dime", "bang-tail", "geezer", "sheezy", "bling-bling", "buzzer", "Butter and eggs man", "the big sleep", "Chinese squeeze", "droppers", "flippers", "flimflams", "scallywags", "lackalacka Moomoo", "feeding the overweight mule", and "starching the bronze weasel." Of course there still are a wide number of slang terms in use, mostly by today's youth, that have vulgar meanings towards a certain group or person, but unlike the old days, these words don't make people generalize all slang as vulgar.
While the origins of slang are fairly well known, the development of slang is cloudy. In other words, we know where slang came from; we just don't know why it came in the first place. The reason for this is that there can be many contributing factors. For example, society in general t...