fistulate /ˈfɪstjʊlət/adjective 1/ˈfɪstjʊleɪt/ verb 1forms 3 adjective1 •Hollowed like a fistula. fistulate /ˈfɪstjʊleɪt/ verb1 •(no longer used) To make or become hollow like a fistula, or pipe. formsfistulated · fistulating · fistulates