Words are not enough when communicating. Context and understanding are crucial. Without context confusion arises to the point of ridiculousness. Let me try to illustrate this by something that I learned in school:
Take the word “nit.” The Concise Oxford English Dictionary defines “nit” as a stupid person, a louse. Then add the letter “k” before the “n” and you have “knit.” Yet the word “nit” from the word “knit” is a whole different kettle of fish. And what is that anyway: a kettle of fish?
Now, let’s take the word “wit:” defined as someone with a sharp sense of humour, a player of words perhaps. As in “that man possesses wit. He has a sharp mind.” But then add the letter “t” before the “w” and you have “twit.” Or, combine the word “nit” with the word “wit” and you have a “nitwit.” But “nit” and “twit” together does not sound quite right – “nit-twit?”
Nonetheless, given that a “nit” is already defined as a stupid person, and “wit” is someone who has a sharp mind, then “nitwit” defiles all logic in a descriptive sense except perhaps to define someone who possesses a stupid “wit” – which in itself is oxymoronic. But “dimwit” already has that locked up. Yet what is really frustrating about the undercurrent of this word is that “dimwit” is the opposite of someone who has a sharp “wit.” So, that being the case, let’s call him or her a “blunt-sharp” person!
To make matters worse a “twit” could be someone who has a sharp “wit,” and is still a “nitwit” or a “dimwit.” So why can’t we call him or her a nit-twit? Or a “dim-twit”? The bottom line is that “nitwit” or “dimwit” sounds better. The other bottom line is that English words are just downright confusing without context and a shared understanding of the contextual environment we are communicating in.