To take something out of context. To consider it separated from related things that are crucial to properly interpreting it. This is primarily an academic term, used in postmodern anthropology and criticism, so it does not relate to quotes or images as much as the more common "out of context." Rather, it is used for ideas and cultureal phenomena. For example, if we decontextualize Hitler he looks uniquely like Satan, but by considering him as part of his time and historial milieu we can see that he was a plausible expression of the very worst elements in European culture, fortuitously situated at the beginning of twentieth-century industrialism when his ideas could be expressed with an efficiency and bureaucratic coldness that was never before possible.