Shocked or greatly surprised; amazed to the point of being stunned or bewildered.
From Old French 'estoner' meaning to stun or daze, from Latin 'ex-' (out) and 'tonare' (to thunder). The word literally means to be thunderstruck, reflecting the overwhelming nature of great surprise.
The connection between thunder and amazement appears in many languages - we say people are 'thunderstruck' when astonished, reflecting ancient beliefs that sudden loud sounds could literally stun or disorient people.
Complete word intelligence in one call. Free tier — 50 lookups/day.