We love to play with our words like a cat and a ball of yarn. We can take a word with a perfectly clear meaning and then turn it around and make it also speak it’s opposite. “That’s so bad” can mean it’s very good. “That’s sick” can also mean it’s good, although I’m not sure why.
We love to turn words into the opposite of what they originally meant. It is such a common hobby, skewing words and redesigning their meanings, that even the word describing that action has several different names.
I find that ambiguity interesting. It is entirely appropriate that this type of word should not have a clearly defined label. Two words to describe this concept were invented in the 1960s. A contronym (or autoantonym) is a word with multiple meanings, one of which is defined as the reverse of one of its other meanings.
This means that when you use these words in your writing you must be sure the context clearly identifies which meaning is intended. English is a fluid, evolving language and, like Latin, will one day be considered an extinct language. Sometimes a language that has changed so much that linguists describe it as a different language (or different stage) is called “extinct”, as in the case of Old English, a forerunner of Modern English.
In many cases, the language never stopped being spoken, it simply evolved. Take Latin, for example: there is no point at which Latin died. Instead, it evolved in different ways in different geographic areas, and its modern forms are now identified by many different names such as French, Spanish, Italian, Romanian, Catalan, Venetian–all the languages we call Romance Languages.
We don’t call them that because they are romantic–in this case the word romantic means originating in Rome. The root of the word Romance is of Rome. Latin is not dead–the roots of Latin form part of the base upon which Modern English is built, and we who proudly speak a variation on Old Saxon use the name of that fabled city-state to describe the most precious and intimate of emotions–that wonderful heady feeling we call romance.
So what words are currently also their own opposites? For a large list, click on this link which will take you to Daily Writing Tips.
My point with all of this is that we must be very clear about the context in which we use certain words, because with the ever-changing world around us, the language we depend on to convey our meanings is changing. I see it as being in a period of change as radical as that of the Renaissance, when literally (which now can also mean figuratively) thousands of words were coined and reinvented.