A person who secretly looks at or investigates things that aren't their business.
From 'snoop' (from Dutch 'snoepen,' to eat or pry) + '-er' (one who does). The word gained prominence in American English in the early 1900s.
Snooper comes from Dutch and means originally to poke at things greedily—it perfectly captures both the busybodiness and the quiet sneakiness of someone poking into others' affairs.
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