A skeuomorph (from the Greek for vessel or tool and shape) is a derivative embellishment that cues an operator to a function by invoking some older physical, mechanical element. The icons of graphic interfaces are vast arrays of skeuomorphs—like the symbol of a paper envelope for e-mail, a pad-lock, a waste-bin. None of these representations exist within the computer—like the orientation of PLAY pointing to the right and REWIND to the left, there being no direction but rather an allusion to mechanism of older video and cassette players, but skeoumorphism is not limited to the quiver of familiar icons.

There's quite a range of abstractions that fall into this category—I think, to include gestures and gesticulations like widely recognized pantomime for call me or for what time is it, though the instruments likely to be used are quite other in form, not to mention things like vestigial cross-beams or pockets or Ersatz books in the office or buttons and the rendering of busyness over the hull of a star-ship that's more decorative than functional—like the Borg Cube or the trench of the Death Star (greebling is the word). There's also the subtler touches, like having a digital camera click its shutter for a satisfying and familiar sound. There has even been proposed legislation that a such devices retain this feature so people know if they are being photographed at close range—and I suppose, so the photographer is making a more conscience decision to take a picture too. Slight and flimsy gadgets are also routinely weighted down with some added metal purely to give the object a feeling of heft and thus better quality.