authenticity
noun [ U ] uk/ˌɔː.θenˈtɪs.ə.ti/ us/ˌɑː.θenˈtɪs.ə.t̬i/
确实性；真实性；可靠性
the quality of being real or true
The poems are supposed to be by Sappho, but they are actually of doubtful authenticity. 据信这些诗是萨福所作，但实际上其真实性令人怀疑。
The authenticity of her story is beyond doubt. 她讲述的事情的真实性不容置疑。