Thomsonian UK /tɒmˈsəʊ.ni.ən/US /tɑmˈsoʊ.ni.ən/adjective 1noun 1forms 3 adjective1 •Relating to Thomsonianism. noun1 •A believer in Thomsonianism; one who practices Thomsonianism. formsThomsonians · more Thomsonian · most Thomsonian