孤本

孤本	gū běn	the only extant copy of a book
孤	gū	lone / lonely
本	běn	(bound form) root; stem / (bound form) origin; source / (bound form) one's own; this / (bound form) this; the current (year etc) / (bound form) original / (bound form) inherent / originally; initially / capital; principal / classifier for books, periodicals, files etc