Skeuomorphism is the practice of including features of old technology in new technology, but as design elements, without their old functionality. Examples include folders in the GUI of a computer to click on to access groups of files and the sound effect on my digital camera that sounds like a shutter clicking whenever I take a picture.
I think you could also extend its use metaphorically to cover terms for new technology that use old technology as a basis for comparison. One example of this type of use would be "horsepower" as a skeuomorph referring to the strength of a car’s engine. Another example would be "astronaut"/"cosmonaut" [literally "star-sailor"/ "universe-sailor" according to the Greek roots] for those who travel in outer space.
This is an extremely useful word, applicable in many instances today. I love it!
Incidentally, the word skeuomorphism has as its roots the Greek terms for "tool" ["skeuo-"] and "shape" [morph"]. Literally it means "a thing shaped like a tool" — with the implication that, although it appears to be a tool, it cannot be used exactly as its appearance suggests. Its very existence interrogates the nature of originality and reality. Whoa, dude — that’s so, like, deep!