To knowingly say that something is smaller or less important than it actually is, especially as a way of showing contempt or deprecation.
To make smaller.
To remove white space and unnecessary characters from a web page's source code in order to reduce its size and improve download time.
To reduce in apparent size, as for example objects viewed through a lens or mirror shaped so as to increase the field of view, such as a convex or aspheric mirror or a Fresnel lens.