'astone' originates from Old French, specifically the word 'estoner', ultimately from Vulgar Latin *extonare (from Latin ex- + tonare).

'astone' changed from Old French 'estoner' into Middle English 'astonen' and later appeared in Modern English as 'astone' with the past form 'astoned'.

Initially it meant 'to strike (as with thunder) or to stun', and over time it evolved into the current sense of 'to astonish; to stun'.