Sentence:  A concrete name is a name which stands for a thing; an <WSD>abstract</WSD> name which stands for an attribute of a thing....A practice, however, has grown up in more modern times, which, if not introduced by Locke, has gained currency from his example, of applying the expression "<WSD>abstract</WSD> name" to all names which are the result of abstraction and generalization, and consequently to all general names, instead of confining it to the names of attributes. 
Meaning of the word marked with <WSD> tags:  Considered apart from any application to a particular object; not concrete; ideal; non-specific; general, as opposed to specific. (First attested around 1350 to 1470.)<ref name=SOED/>