roller

A "roller" is usually something round that turns and helps things move, press, or spread smoothly. You see it in everyday life in a *paint roller, in roller skates*, and in machine parts that carry things along or help them turn.

The word also appears in a few other common ways. A *hair roller is used to curl hair, and a steamroller is a heavy road machine that presses the ground flat. It can also mean a person whose job is to roll something, such as a cigar roller. In another sense, a roller* can be a long, strong wave moving toward the shore.

The word "roller" most often refers to a round object that turns as it moves or presses against something. That basic idea shows up in many places: a *paint roller spreads paint across a wall, conveyor rollers help move goods through a machine, and roller bearings* help parts turn more smoothly. In all of these cases, the shape and motion of the object are the key idea.

The word is also used for tools and vehicles built around that turning shape. A *hair roller is a small tube used to curl hair. A steamroller is a heavy vehicle with large rollers that flatten and level a road surface. In some cases, the word can describe a person whose work involves rolling something by hand, such as a cigar roller*.

"Roller" also has a few extended meanings. In coastal language, it can mean a long, powerful wave moving toward the shore. In everyday speech, a *high roller is a person who spends or gambles large amounts of money, especially in a casino. There is also a bird called a roller*, named for its rolling or tumbling motion in flight, though that sense is less common in ordinary conversation. Across these uses, the word keeps the same basic feeling of turning, rolling, or moving in a smooth, powerful way.