authenticity

Etymology

authentic + -ity

noun

1. The quality of being genuine or not corrupted from the original, of having the same origin (or attribution, commitment, intention, etc.) as claimed.
   I hereby certify the authenticity of this copy.
   The authenticity of this painting is questionable.
   Urban Dictionary records at least 66 of the terms found by the present research, but as this dictionary liberally accepts words, definitions, and sample sentences based solely on the say-so of contributors, in the absence of corroboration from other sources the authenticity of some entries must remain dubious. 2018, James Lambert, “A multitude of ‘lishes’: The nomenclature of hybridity”, in English World-Wide, page 2
2. (obsolete) The quality of being authentic (of established authority).