Final answer:
The five-letter word found in two of the top four U.S. newspapers by circulation is 'Times', specifically in the names of the New York Times and the Los Angeles Times.
Step-by-step explanation:
The two of the top four U.S. newspapers by circulation that have a common five-letter word in their names are the New York Times and the Los Angeles Times. These prominent newspapers have a widespread readership both in print and online, reflecting the enduring significance of newspapers in the dissemination of news, despite the media's shift towards digital platforms and the challenges it faces within the industry.