Impressed someone greatly or caused them to feel amazement and admiration.
From Scottish English 'wow' (to impact/strike), possibly imitating an exclamation of amazement. The word gained popularity in the early 1900s and may relate to onomatopoeia.
The word 'wow' is probably imitative—it sounds like what you say when you're suddenly impressed, which makes it one of the most honest words in English because it literally sounds like the feeling!
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