Plural of bunko; multiple swindles, fraudulent schemes, or instances of bunco gambling.
From 'bunko' (variant spelling of 'bunco'), a confidence game term from the 1870s, pluralized to refer to multiple instances of fraud.
In old newspapers, you'd see warnings about 'bunkos' happening in cities—it was basically 19th-century internet scams, except criminals worked the streets instead of email!
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