PERUSE: “read thoroughly or carefully; examine carefully or at length” — New Oxford American Dictionary
Finally, an attempted lexicide that seems to be recovering. Casual users have been abusing the word peruse for decades, taking it to mean the opposite of what it does mean. How many times have I been asked to “quickly peruse” a document, or heard the abashed admission that “I only had time to peruse your proposal,” or (my favorite) the offhand suggestion that something was “not that important — just peruse it if you have time?”
In all these cases, folks used peruse to mean “read quickly,” for which there is one incontrovertible synonym that captures the same nuances: skim. Also closely related are scan, browse, glance at and flip through. In its true definition, study is probably the best synonym, followed by scrutinize, pore over and scan (see note below). So why is peruse used incorrectly? Once again, someone should have dusted off the old Webster’s when the boss-man produced a sheaf of papers and gave orders to peruse. It’s bad enough the poor illiterate misunderstood, skimmed the materials and still managed to impress the board; worse still that he or she propagated the misuse upon being promoted.
Peruse doesn’t seem to have become a corporate buzzword, so its misuse is poorly anchored. As a result, the word seems to be falling out of favor. No dictionary I have consulted offers “read quickly and fleetingly” as a definition. The American Heritage Dictionary (Fourth Edition) includes a special usage note warning against this definition. Indeed, its usage board voted it down 58% to 42% in 1999 (although the margin was 66% – 34% eleven years earlier). An article by the venerable Michael Quinion of World Wide Words seems to imply that peruse is not — and has not been — commonly used in the UK in modern times. All of this means the word may soon shed its faulty definition altogether.
Note: Scan traditionally has meant “to look…carefully in order to detect some feature” (NOAD). Probably through the influence of electronic scanners, which examine carefully, but quickly, scan now means both peruse and skim. Interestingly, the distinction seems to be this: scanning the distance takes time and care; scanning something close (like a book) does not.
— Otto E. Mezzo
Reference: http://www.worldwidewords.org/qa/qa-per1.htm