astonish

From an alteration (due to words ending in -ish: abolish, banish, cherish, establish, furnish, etc.) of earlier astony, astone, aston, astun (“to astonish, confound, stun”), from Middle English astonien, astunien, astonen, astunen, astounen (“to astound, stun, astonish”), of uncertain origin, possibly from Old English *āstunian, from ā- (perfective prefix) + stunian (“to make a loud sound, crash, resound, roar, bang, dash, impinge, knock, confound, astonish, stupefy”), from Proto-Germanic *stunōną (“to sound, crash, bang, groan”), from Proto-Indo-European *(s)ten-, *(s)ton- (“to thunder, roar, groan”), equivalent to a- + stun. Compare German erstaunen (“to astonish, amaze”). Another possible source, or else influence, is Old French estoner, estuner, estonuer, estonner (“to stun”), either from an assumed Vulgar Latin *extonāre (“to strike with thunder, daze, stupefy, stun”) from *extonō (ex + tono), or from Old Frankish *stunen (“to stun”), related to Middle High German stunen (“to knock, strike, stun”) and then, if not the source, still a cognate of the word astound.