na-adjective
Used as a na-adjective to describe something genuine, original, or true to its origins. Common in fashion, food, and cultural contexts.
このレストランはオーセンティックなイタリア料理を出す。
This restaurant serves authentic Italian cuisine.
彼のスタイルはとてもオーセンティックだ。
His style is very authentic.
本格的 is a native Japanese na-adjective meaning 'full-scale' or 'genuine', often used for serious or thorough endeavors. オーセンティック carries a nuance of being true to original traditions or origins, especially in cultural or stylistic contexts.
Loanword from English 'authentic'.