'astone' originates from Old French, specifically the word 'estoner', where 'es-' (a prefix) + 'toner' (from Latin 'tonare') meant 'to stun or strike (as by thunder)'.

'astone' changed from Middle English 'astonen' (borrowed from Old French 'estoner') and was used in Early Modern English; it is now largely archaic.

Initially, it meant 'to strike or stun (as if by thunder)', and over time it evolved into the more general sense 'to astonish or overwhelm', which is mostly preserved though the word itself became rare.