Sentence:  Dialect has by now been used in so many senses that any definition will automatically be too narrow: for what we have here is a pre-scientific, folk <WSD>taxonym</WSD> (though a very useful <WSD>taxonym</WSD>) that is incapable of precise definition. 
Meaning of the word marked with <WSD> tags:  A word used for classification purposes, that is, one that makes up part of a taxonomy.