spuriosity UK /spjʊə.ɹiˈɒ.sə.ti/US /spjʊ.ɹiˈɑ.sə.ti/ noun2 •(rare) Spuriousness.The supposition that authors have a preternatural ability to detect spuriosity in writing is as false as the comparable belief that their literary practices make them unerring as literary critics. — 2001 •(rare) That which is spurious; something false or illegitimate. formsspuriosities