Meaning

verb make keen or more acute

verb sharpen by rubbing, as on a whetstone

originThe verb is derived from Middle English whetten (“to make the edge of (a sword, tool, etc.) sharp; to grunt, snort; to scrape the ground with (one’s feet); to make a chattering or grinding sound; (figurative) of a person: to prepare for battle; to make (one’s wit) alert or keen; to strengthen (one’s heart or will); to incite, provoke”), from Old English hwettan (“to sharpen, whet; (figurative) to…

Etymology from Wiktionary, CC BY-SA 3.0