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acnode

noun
  1. a point whose coordinates satisfy the equation of a curve although it does not lie on the curve; an isolated point. The origin is an acnode of the curve y ² + x ² = x ³
Derived Formsacnodal, adjective

Word Origin for acnode

C19: from Latin acus a needle + node
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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Historical Examples of acnode