(n) genuineness or spuriousness; authenticity; the genuine and the spurious
鑑定をする時には、絵の真贋や保存状態等を調べる為、持ち主に本物を借りたりしなければいけなくなる。
When it is appraised, in order to check the authenticity and state of preservation of the painting, the real thing has to be borrowed from its owner.