AUTHENTICITY
authenticity, genuineness, legitimacy
(noun) undisputed credibility
Source: WordNet® 3.1
Etymology
Noun
authenticity (usually uncountable, plural authenticities)
The quality of being genuine or not corrupted from the original.
Truthfulness of origins, attributions, commitments, sincerity, and intentions.
(obsolete) The quality of being authentic (of established authority).
Synonyms
• (quality of being genuine): genuineness
Antonyms
• (quality of not being genuine): phoniness; forgery; fakeness; bogosity
Source: Wiktionary
Au`then*tic"i*ty, n. Etym: [Cf. F. authenticité.]
1. The quality of being authentic or of established authority for
truth and correctness.
2. Genuineness; the quality of being genuine or not corrupted from
the original.
Note: In later writers, especially those on the evidences of
Christianity, authenticity is often restricted in its use to the
first of the above meanings, and distinguished from qenuineness.
Source: Webster’s Unabridged Dictionary 1913 Edition