Rebecca was an academic star. Her new book was on the phenomenon of word casings, a term she'd invented for words that no longer had meaning outside quotation marks. English was full of these empty words--"friend" and "real" and "story" and "change"--words that had been shucked of their meanings and reduced to husks. Some, like "identity" and "search" and "cloud," had clearly been drained of life by their Web usage. With others, the reasons were more complex; how had "American" become an ironic term? How had "democracy" come to be used in an arch, mocking way?