a.

1. 可信的，真實的，可靠的
   The report is authentic.

   這個報告是可靠的。

2. 真正的，非假冒的[Z]
   They found this authentic manuscript of the book from an ancient tomb.

   他們從一個古墓裡發現了該書的真正手稿。

3. （依法）有效的，手續齊備的

adj.

1. of undisputed origin or veracity; genuine.
2. Music  (of a church mode) containing notes between the principal note or final and the note an octave higher. Compare with plagal.