Mirriam Webster: producing, relating to, or marked by intentional distortion (as by unequal magnification along perpendicular axes) of an image
Anamorphic lenses are used to film and project very wide film formats, for example, using film in a more typical aspect ratio.
Here are a couple of anamorphic photoshops of scenes which are scaled to decrease the horizontal pixel count, while retaining the vertical pixel count, with resampling:
These are also anamorphic projections, via conversion in photoshop to polar coordinates.
Etymology:
Anamorphosis is a distorted projection or perspective requiring the viewer to use special devices or occupy a specific vantage point to reconstitute the image. The word "anamorphosis" is derived from the Greek prefix ana-, meaning back or again, and the word morphe, meaning shape or form.
Note that the reversible nature of the projection is implied in the word roots.