astound
‘to astonish and bewilder’
Lexical development traced from the Tamil root:
E. astuned, astownyd, astownd < M.E. astouned, astoned, past participles of astonen, astonien ‘to stun’ (similar to the pattern applied for the verb round ‘to make round’ from the adjective round ‘spherical in shape’ ) < tawn < ret- < Tamil uruḷ
Semantic evolution: The word may have been evolved out of the meaning of ‘making someone's head spin.’