Defamiliarization refers to a writer's taking an everyday object that we all recognize and, with a wave of his or her authorial magic wand, rendering that same object weirdly unfamiliar to us—strange even. Presto change-o, our perspective shifts and we see the object in a new way. A pretty neat magic trick, if you ask us.
The word defamiliarization was coined by the early 20th-century Russian literary critic Viktor Shklovsky in his essay "Art as Technique." He argued that defamiliarization is, more or less, the point of all art. Art makes language strange, as well as the world that the language presents.
Instances of defamiliarization are rampant in genres like science fiction and travel narratives. For example, we see the effects of defamiliarization in Jonathan Swift's satiric travel story Gulliver's Travels when Gulliver visits the land of the giant Brobdingnabian people and gets a glimpse of the women's skin pores up close:
This made me reflect upon the fair skins of our English ladies, who appear so beautiful to us, only because they are of our own size, and their defects not to be seen through a magnifying glass, where we find by experiment that the smoothest and whitest skins look rough and course, and ill colored. (Part 2, Chapter 1)
Notice how Gulliver's size makes the women look just plain ugly? Something once beautiful, fair, and familiar is now totally strange.