a piece of special flat glass that reflects images, so that you can see yourself when you look in it

something that shows what something else is like

The face is the mirror of the soul.

Dickens' novels are a mirror of his times.

a website that is a copy of another website but that has a different address on the internet

to have features that are similar to somebody/something else and that show what it is like

to show the image of somebody/something on the surface of water, glass, etc.

She saw herself mirrored in the window.

The houses lining the fjord were mirrored in its calm surface.

LEARNit Dictionary