I would urge you to, like I realised I had to a few years ago, get over it. Language is not defined by a dictionary or by history; roots and origins are truly meaningless. A word is defined by its usage; it’s one of the delightful things in the world for which it can be said that if enough people say something is true, it becomes true.

Uniqueness may once have been a boolean property (I cannot say for certain one way or another), but at present it is not.