Jargon

"Why can't the English teach their children how to speak?" -- Prof. Henry Higgins

America and England: "Two countries separated by a common language." -- Winston Churchill.

Student: "Is that a word?"
Professor: "It is now, you just used it."
Student: "But it's not in the dictionary."
Professor: "Maybe not yet. Meanwhile, get a new dictionary."

   Words travel with the speed of a new joke.
   Slang or jargon begins with "in" terms invented and used by small groups to enhance communication among insiders, and limit access by outsiders. Slang then spreads to the population at large and becomes recognized as part of the language.
   Acceptability, however, varies with the prestige of the originating group. When a new word or term gains usage in a larger or more prestigious group, moreover, its acceptability accelerates. Meanwhile, the originating group may move on to invent newer words. (Ask any teenager. As soon as their parents pick up new slang, teens drop it and invent another term.)

   Slang and jargon are two forms of borrowing, as words move from one linguistic group to another, whether a regional or social dialect or a distinct language. Sometimes, moreover, the same term may enter another language twice, taking on different meanings as they do. On example is chef and chief. Both come from French, and each refers to someone in charge -- the first specific to a kitchen, and the second more general.
   In America, dozens of words have been borrowed from Spanish, especially in the Southwest and West, then spreading to general, nationwide usage. Examples here include lariat and rodeo.   Minority groups also contribute new words to the language. Maven, an expert, is a Yiddish term carried forward from Hebrew, gaining currency in coastal and metropolitan areas, and moving on to nationwide usage. Musicians regularly supply new terms.
   English itself is an amalgam of many languages, using Anglo-Saxon, a Germanic dialect, as a base, and incorporating words from Latin, French, Gaelic and Welsh as it grew from its origins in Britain to America and Canada, Australia, New Zealand, India and other nations around the world, picking up many new words along the way.
   American English continues that tradition, borrowing and incorporating words from native tribal languages as well as from newcomers who add to the mix.
   America has been called a melting pot, but it's more accurate to say it's a kaleidoscope of many cultures and languages, all contributing to the diversity of America. It must be admitted, however, that not all terms make the trip to a larger world, and remain in specific regions. One such is oxter, a word common across the pond, but not in America. (Look it up.)

   The study of linguistic variation began as dialectology, which looked at regional differences. In the mid-20th Century, however, it was displaced and incorporated into the wider field of study known as sociolinguistics, which identified differences according to social class as well as geographic region.
   And with the study of language differences comes the study of social attitudes. Just as slang and jargon serve to identify members of a group, so does pronunciation. In fact, that tactic goes back millennia, to the use of shibboleth, a word an early Hebrew tribe used to identify fleeing enemy warriors of a competing tribe, who pronounced the word as sibboleth.

     All the while, keep in mind that a dictionary is a history book, not a law book. It lists words that people have used, giving definitions and providing pronunciation guides. In fact, dictionaries began life as pronunciation guides for those in the newly wealthy merchant class who wanted to be accepted by the aristocracy.
   Variations of that strategy are still useful. Broadcast news announcers all use the dominant America dialect known as North Midland, which spreads from the Northeast and widens as it moves westward, farther from East Coast major cities. Political candidates, too, shift to a regional dialect with greeting voters back home, and return to the more prestigious dialect when in Washington.