classical music. In technical musical usage this means music composed during the late eighteenth and early nineteenth centuries, characterized by the development of the sonata by such composers as Mozart. In popular use, however, the term is used to mean any serious art music as distinct from jazz, pop, or folk.
The definition of vague is something unclear, hazy or uncertain. An example of vague would be directions to a house that don't include street names. YourDictionary definition and usage example.
Problematic vagueness: The characteristic of a word or expression as having an imprecise meaning or unclear boundaries in a given context or for a given purpose. The characteristic of a word or expression as referring to more than one object or as having more than one meaning in a given context or for a given purpose.