A titter is a nervous, partly suppressed little laugh, the kind that slips out when you're trying to stay quiet but can't quite manage it. It's higher and lighter than a regular chuckle, more of a giggle that someone's attempting to hold back.

You might hear tittering in the back of a classroom when someone makes an awkward mistake, or when a group of kids is trying not to laugh during a serious assembly. The word captures that specific sound of people laughing quietly together, often because they know they shouldn't be laughing at all. When your friend whispers something funny during a library period and you can't help but let out a quick, stifled laugh, that's a titter.

The word often suggests that people are laughing at something slightly embarrassing or inappropriate, which is why they're trying to keep it quiet. If a teacher mispronounces a word in a funny way, students might titter behind their hands. It's the laugh of people who are amused but also aware they're in a situation where full laughter wouldn't be quite right.