known to be true or genuine 真实的; 真正的: an authentic document, signature, painting 正式文件﹑ 亲笔签字﹑ 原作绘画. 
trustworthy; reliable 可信的; 可靠的: an authentic statement 可靠的陈述.> authentically / -klI; -klI/ adv.
authenticity / 9R:Wen5tIsEtI; 9RWEn`tIsEtI/ n [U] quality of being authentic 真实性; 可靠性; 确实性: The authenticity of the manuscript is beyond doubt. 手稿的真实性是毋庸置疑的.