In his book Alphabet Juice, Roy Blount Jr. coins(?) the word sonicky, which refers to words that sound like what they mean. In his words, "I mean the quality of a word that doesn't imitate a sound, but does somehow sensuously evoke the essence of the word." A word like greasy might be an example of sonicky, or, according to him, mumble and muffle.
I would imagine that others might contend that the words came first, the fact that they sound right is because we know their meaning.
I read somewhere that the reason people with Tourette Syndrome swear isn't so much because they're swearing, but because we naturally enjoy and gravitate toward words with a hard "k" sound. Which I could buy, because boy, do I love words that end in the hard "k" sound. One word in particular.
So I noticed something recently. I was thinking about the word skeptic, and why it has a negative connotation. Maybe I'll do a longer entry on it later. Skepticism, my skepticism, is only about wanting evidence - a skeptic doesn't scoff, a skeptic is simply a person who, if you offer to sell her some new-fangled snake oil, is going to demand some scientific evidence that it's effective. To me that's not any kind of scorn, we just don't like to be scammed by sketchy scum.
Other "sk" words - scold, scald, sketchy, scat, skids, skid row, skimp, tsk. And those are only words that start with the sk sound.