Sharp as a razor.
The etymology is a little unclear but the most logical deductions bring us these possible routes:
The Greek Xyster, a tool for scraping bone, from Xuein meaning to scrape, make smooth.
There is also the Greek Xiphos, a kind of double-edged short sword.Usage:
"We may not be able to boast of our xyresic wit but our swords are sharp and dissected men have more to worry about than snarky remarks."
Love Tahlia, colder than a frozen tundra.