A magnifier is a tool that makes things look bigger than they really are. The most common type is a magnifying glass, which has a curved piece of glass or plastic called a lens that bends light in a way that enlarges whatever you're looking at. Hold a magnifying glass over a book and the letters appear much larger. Move it over an insect and you can see details invisible to your naked eye.

Scientists use powerful magnifiers called microscopes to study tiny things like cells and bacteria. Detectives in stories often carry magnifying glasses to examine clues at crime scenes. Jewelers use special magnifiers to inspect diamonds and other precious stones for flaws.

The word can also describe anything that makes something seem more significant or noticeable. A crisis might act as a magnifier of problems that were already there but easy to ignore. Your nervousness before a presentation might be a magnifier that makes small mistakes feel enormous.

When something magnifies, it literally or figuratively makes things seem greater or larger than they appear without help.