whet v.

Old English hwettan "to whet, sharpen," figuratively "incite, encourage," from Proto-Germanic *hwatjan (source also of Old Norse hvetja "to sharpen, encourage," Middle Low German, Middle Dutch wetten, Old High German wezzan, German wetzen "to sharpen," Gothic ga-hvatjan "to sharpen, incite"), from PIE root *kwed- "to sharpen" (source also of Sanskrit codati "incites," literally "sharpens;" Old English hwæt "brave, bold," Old Saxon hwat "sharp").