'astonied' originates from Old French, specifically the word 'estoner', where the prefix 'es-' served as an intensifier and the root related to Latin 'tonare' meaning 'to thunder'.

'astonied' changed from Middle English forms such as 'astony' and verbs like 'astonien' (from Old French 'estoner') and eventually existed in English as the adjective 'astonied' meaning 'stunned'.

Initially it carried the sense of being struck (figuratively) as if by thunder — 'to stun' — and over time evolved into the current sense of 'stunned' or 'astonished'.