Over time, linguistic expressions come and go. Some of them are generational – every generation coins terms that become popular like “cool,” “rad,” “stoked,” and many others. When a new generation comes along, these terms usually disappear as new ones emerge.
Some other words are derogatory and disappear when they are deemed by society as repugnant. Some of these were originally intended to be insulting – like the “N word” that was used for blacks, “Whitey” that was an insult toward whites, or “Krouts” and “Japs” that were used to insult the Germans and Japanese during and after WWII. These kinds of words tend to go away over time as they are deemed by society to be insulting and distasteful.
There is another category of words that might get expunged from the lexicon because of political correctness. These are words that originally had no negative connotation at all, but at some point some group of people began taking offense and started working to apply social pressure to stop them from being used. Words in this category might include “girls,” “retarded,” “stewardess,” and one in the news these days, “alien.”
Now, PETA (People for the Ethical Treatment of Animals) is working on a new category. (Read the rest of the article here.)