Verb or Noun: Small sound that is emitted through the nose and mouth, usually a compressed laugh or snort. Often accompanied with a small grin, smirk, or sneer. Usually a tone of either derision, (as when someone says something you find stupid) or innocent humor. (When someone tells you a funny joke and you are busy doing something else, so a full-fledged laugh is difficult.)Nice to use behind other's backs, as when they do something inanely stupid and you can't help but laugh about it, but don't want to fall over laughing.
Holding my lunchtray in one hand and balancing my fork, I snerked as Caroline delivered the punchline of the dead baby joke
When the girl in front of me pointed at the Mustang and said, "Oh, I like that Camaro.", I had to snerk discreetly.