Vandemonian UK /ˌvæn.dɪˈməʊ.ni.ən/US /ˌvæn.dɪˈmoʊ.ni.ən/noun 2adjective 1forms 1 noun2 •(informal) A person from Tasmania. •(historical) A person from Van Diemen's Land. adjective1 •Relating to Tasmania or Van Diemen's Land. formsVandemonians