A cutter is a type of boat designed to be fast and agile. Traditional cutters have a single tall mast (the vertical pole that holds the sails) and carry multiple sails that can be adjusted to catch the wind from different angles. The U.S. Coast Guard uses cutters as their main vessels for rescuing people at sea, enforcing maritime laws, and patrolling coastlines. These modern Coast Guard cutters are powered by engines rather than sails, but they keep the name from their sailing ship ancestors.

The word also describes someone whose job involves cutting: a glass cutter scores and splits glass for windows, a stone cutter shapes blocks for buildings, and a film cutter (now usually called an editor) pieces together scenes to create movies.

In school or office supply contexts, a cutter is a tool with a sharp blade used for precise cutting, like a paper cutter that slices through stacks of paper in one clean motion, or a box cutter with a retractable blade for opening packages.

Less commonly, cutter can refer to a small sleigh pulled by one horse, popular in the 1800s for winter travel when snow covered the roads.