Tanchelmian adjective 1noun 1forms 3 adjective1 •Of or relating to Tanchelm (died 1115), a heretical itinerant preacher, critical of the established Roman Catholic church, active in the Low Countries around the turn of the 11th and 12th centuries. noun1 •(historical) A religious supporter of Tanchelm. formsTanchelmians · more Tanchelmian · most Tanchelmian