au·then·tic / ôˈ[unvoicedth]entik/ (abbr.: auth.) • adj. 1. of undisputed origin; genuine: the letter is now accepted as an authentic document. ∎  made or done in the traditional or original way, or in a way that faithfully resembles an original: the restaurant serves authentic Italian meals ∎  based on facts; accurate or reliable: an authentic depiction of the situation. ∎  (in existentialist philosophy) relating to or denoting an emotionally appropriate, significant, purposive, and responsible mode of human life.2. Mus. (of a church mode) comprising the notes lying between the principal note or final and the note an octave higher. Compare with plagal.DERIVATIVES: au·then·ti·cal·ly / -ik(ə)lē/ adv.au·then·tic·i·ty / ˌô[unvoicedth]enˈtisitē/ n.

authentic †authoritative XIV; entitled to acceptance or belief as being reliable; actual, not imaginary XV; genuine, not counterfeit XVIII. ME. au(c)tentik — OF. autentique — late L. authenticus — Gr. authentikós; see -IC.