snap
To break or move suddenly with a sharp, quick sound.
To snap means to break suddenly with a sharp cracking sound. A dry twig snaps when you step on it. A pencil snaps in half if you bend it too far. The word captures both the action and the crisp sound that happens at the same moment.
Snap also means to move or speak with sudden quickness or sharpness. A turtle snaps at your finger. A person might snap at you with an irritated reply if they're having a bad day: “I'm fine!” instead of a patient answer. Your fingers snap when you press your thumb and middle finger together and flick them apart to make that clicking sound.
In photography, a snap is a quick, casual picture. Your mom might take vacation snaps on her phone. Snapshots capture moments without elaborate setup or posing.
When something is easy, you might say it's a snap, meaning it requires little effort. If math homework is a snap for you, you finish it quickly without struggle.
The phrase snap out of it means to suddenly stop a mood or behavior: “Snap out of it and focus!” A cold snap is a sudden period of cold weather. Each meaning shares that sense of suddenness: sharp, quick, immediate.