The paper summarises the author's findings which result from his experience as the chief lexicographic editor, as well as co-author, of the New Comprehensive Russian- English Dictionary , now being prepared for print by Russky Yazyk Publishers in Moscow, Russia, to replace the well-known but long outdated dictionary by A. Smirnitsky. It is demonstrated how a bilingual dictionary may need to be revised and restructured in line with language evolution over time. The Russian / English language combination serves as a particularly interesting illustration of that need, considering the sweeping changes both languages, but especially Russian, went through in the last two decades of the 20th century. The author's analysis indicates that those changes did not simply involve a large number of new additions to vocabulary and phraseology, but also some broader and more subtle tendencies, which were far from obvious and may have even gone unnoticed by the general community of language speakers.