Akademik

authentic
adj.
1 a of undisputed origin; genuine. b reliable or trustworthy.
2 Mus. (of a mode) containing notes between the final and an octave higher (cf. PLAGAL).
Derivatives:
authentically adv. authenticity n.
Etymology: ME f. OF autentique f. LL authenticus f. Gk authentikos principal, genuine

Useful english dictionary. 2012.