Smiles Filled with Laughter

I've always been intrigued by the etymologies of interesting words. I'm no Latin scholar -- the closest I've gotten is figuring out the basic "amo, amas, amat..." for the purposes of crossword puzzles -- but I do sometimes enjoy dissecting words to find out how they were formed. As a quick example, take the word "awful". In daily speech, this word implies that something is bad or distasteful. But if you look at it literally, the word breaks down into two halves: "awe" + "ful". Nothing in the word itself connotes badness; instead, it should produce awe. Things that are "awful" should fill you with amazement and wonder, not disdain.

En Español, the word for smile is sonrisa. A mi me gusta cuando estás sonriendo -- "I love it when you are smiling." This is, of course, a misnomer -- most English-speaking people would see the word "sunrise" practically leaping out at them. That is, however, a beautiful thought: that one might confuse a smile with a sunrise, or vice versa.

What make this even more interesting to me is, again, the two halves of the word. If you break this noun in half you have "son" + "risa". Son, when taken as a noun, means "sound". Risa, interestingly, means "laughter". Laughter sound. But isn't laughter already a sound? It seems backwards to me. Shouldn't the word for "laughter" be smile sound? Wouldn't that make more logical sense? I also thought that, perhaps, son was originally sin, meaning "without". But that makes it "without laughter," which may technically be true of a smile, though it implies to me that you're probably not full of glee, which would minimize the appearance of said smile, as well.

Anyway, I'm happily perplexed. What do you think? I'd love to hear responses of any kind: Your thoughts on the sonrisa puzzle; other misnomers or poetically constructed words in English or any other language; or any other words with etymologies que causa una sonrisa.