A bullet is a small metal projectile fired from a gun. When someone pulls the trigger, gunpowder explodes inside the weapon, launching the bullet forward at tremendous speed. Bullets come in different sizes and shapes depending on what kind of gun fires them: a tiny .22 caliber bullet used for target practice looks very different from the large bullets used in hunting rifles.

The word also appears in several common expressions. When you bite the bullet, you force yourself to do something difficult or unpleasant that you've been avoiding, like finally cleaning your messy room or admitting you broke something valuable. To dodge a bullet means you narrowly avoided something bad happening, like when a surprise quiz gets canceled just as you realize you forgot to study.

In writing, a bullet point (•) is a dot used to mark items in a list, making information easier to read and organize. These dots got their name because they look like little bullets.

A bullet train is a high-speed passenger train, named for its sleek, pointed shape and incredible speed. Japan's Shinkansen bullet trains can travel over 200 miles per hour, looking almost like bullets themselves as they race along the tracks.