Carthusian UK /kɑːˈθjuːzi.ən/US /kɑɹˈθuʒən/noun 2adjective 1forms 3 noun2 •A member of a Christian contemplative order of monks founded by Bruno of Cologne (St Bruno) in 1084. •A pupil of Charterhouse School (founded in a Carthusian monastery) adjective1 •Of, or relating to this order. formsCarthusians · more Carthusian · most Carthusian