Ballpoint (noun)

1. A type of pen that uses a small rotating ball in its tip to dispense ink onto the paper, resulting in a fine, consistent line.
2. A ballpoint pen is also called a ballpen, biro, or rollerball pen.

Origin:

From ball + point, referring to the ball in the tip of the pen that rotates as the pen is written with, allowing ink to flow onto the paper.

Examples:

1. She wrote her shopping list with a ballpoint pen.
2. He carried a ballpoint pen in his shirt pocket at all times.
3. The ballpoint pen was a reliable and convenient writing instrument.
4. The ballpoint pen replaced the fountain pen as the preferred writing tool for many people.
5. Ballpoint pens are available in a variety of colors, ink types, and tip sizes to suit different preferences and needs.