Authentic

1. n. An original (book or document).
2. n. Having a genuine original or authority, in opposition to that which is false, fictitious, counterfeit, or apocryphal; being what it purports to be; genuine; not of doubtful origin; real; as, an authentic paper or register.
3. n. Authoritative.
4. n. Of approved authority; true; trustworthy; credible; as, an authentic writer; an authentic portrait; authentic information.
5. n. Vested with all due formalities, and legally attested.
6. n. Having as immediate relation to the tonic, in distinction from plagal, which has a correspondent relation to the dominant in the octave below the tonic.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.