Snide Snide is an expression of contempt. I'm too young to know what contempt means, so I'll look that up too. Contempt means intense dislike accompanied by disrespect. So, in order to be snide, you must first feel contempt. According to deductive reasoning, if you don't have contempt, then you can't be snide or make remarks that are snide. What a horrible word, snide. It sounds like snake.
Snarky To understand the meaning of the word snarky, I had to look up irascible. It means easily angered or prone to outbusts of anger. Snarky sounds like scary, and people who are snarky are indeed quite scary.