The state of being in error; the quality of being erroneous.(noun)
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Use "erroneousness" in a sentence
"Even if this land was acquired according to all the relevant laws of the time, the Jews were wrong – just like the British aristocrats in happy Valley during the British rule there, despite the erroneousness of the analogy."
"I was immediately struck by the chutzpah of Sullivan's statement -- both because of its erroneousness and because he had the audacity to make it."
"I've questioned its fundamentality and erroneousness..."