to fill with sudden and overpowering surprise or wonder; amaze: Her easy humor and keen intellect astonished me.
Origin: 1525–35; Middle English astonyen, astonen, probably < dialectal Old French *astoner,Old French estoner < Vulgar Latin *extonāre, for Latin attonāre to strike with lightning, equivalent to ex-ex-1, at-at- + tonāre to thunder; extended by -ish2, perhaps reflecting Anglo-French *astonir < dialectal Old French
[C15: from earlier astonyen (see astonied), from Old French estoner, from Vulgar Latin extonāre (unattested) to strike with thunder, from Latin tonāre to thunder]
mid-14c., astonien, from O.Fr. estoner "to stun, daze, deafen, astound," from V.L. *extonare, from L. ex- "out" + tonare "to thunder" (see thunder); so, lit. "to leave someone thunderstruck." The modern form (influenced by English verbs in -ish, e.g. distinguish, diminish)