12. A handheld electronic book reader, comprising: a memory; a display; and program code configured to control the display to display at least a portion of an electronic document stored in the memory to a user, the program code further configured to select a portion of the electronic document in response to user input directed to the portion of the electronic document, wherein the selected portion includes a passage from the electronic document, create a context for a defined term in the electronic document by associating the selected portion with a definition for the defined term, wherein the selected portion that is selected in response to user input and that is associated with the definition for the defined term in the created context includes content other than the defined term to illustrate an exemplary usage of the defined term in practice, display the definition of the defined term in response to user input, and display the context in association with displaying the definition.
12. A handheld electronic book reader, comprising: a memory; a display; and program code configured to control the display to display at least a portion of an electronic document stored in the memory to a user, the program code further configured to select a portion of the electronic document in response to user input directed to the portion of the electronic document, wherein the selected portion includes a passage from the electronic document, create a context for a defined term in the electronic document by associating the selected portion with a definition for the defined term, wherein the selected portion that is selected in response to user input and that is associated with the definition for the defined term in the created context includes content other than the defined term to illustrate an exemplary usage of the defined term in practice, display the definition of the defined term in response to user input, and display the context in association with displaying the definition. 14. The handheld electronic book reader of claim 12 , wherein the program code is further configured to export the context.