A razor is a sharp tool designed for cutting hair very close to the skin, especially for shaving facial hair or removing unwanted hair from other parts of the body. The most common type is the safety razor, which has a protected blade that slides smoothly across skin without cutting it (usually!). Disposable razors, which people throw away after a few uses, work the same way but cost less.

Before safety razors were invented in the early 1900s, men used straight razors: long, exposed blades that folded into handles. These required real skill to use safely, which is why many men visited barbershops for professional shaves. Today, straight razors are mostly used by traditional barbers and shaving enthusiasts.

The word also appears in expressions about sharpness and precision. A razor-sharp mind means someone thinks clearly and quickly. Walking a razor's edge means being in a precarious situation where one small mistake could lead to disaster. Occam's razor is a philosophical principle that says the simplest explanation is usually the right one, named after a medieval philosopher who used sharp reasoning to cut away unnecessary complications in arguments.

Electric razors, invented in the 1930s, use rapidly moving blades behind a protective screen, making shaving faster and reducing the risk of cuts and nicks.