Refuse, rubbish, or people considered to be of low social status (often considered offensive).
Possibly from Middle Dutch 'raf' (rubbish) or Old Norse 'raf' (rags). The word historically meant worthless scraps and was later applied derisively to people.
The phrase 'riffraff' comes from this word—'riff' and 'raff' were old rhyming words both meaning worthless stuff, so people said both together to emphasize how dismissive they were being!
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