postnational /ˌpəʊstˈnaʃənəl/ adjective1 •Pertaining to a time or mindset in which the identity of a nation is no longer important.The book is “a landmark in what’s possible for the novel” in “our increasingly, and terrifyingly, postnational world,” our reviewer, Jonathan Lethem, said. — 2009 formsmore postnational · most postnational