The quality or state of being rude, crude, or disrespectful in behavior or manner.
From 'boorish' plus the noun-forming suffix '-ness'. The combination creates an abstract noun describing the characteristic or condition of displaying boorish behavior.
Adding '-ness' to an adjective is one of English's oldest tricks for turning qualities into nouns—it's why we can talk about 'sadness,' 'kindness,' and 'boorishness' all the same way. This pattern goes back over a thousand years!
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