antitumor adjective 1noun 1forms 3 adjective1 •Inhibiting the development of a tumor. noun1 •Any substance that inhibits tumors.Aziridines are present as structural motifs in a variety of strongly biologically active compounds such as azinomycins A and B […] which are potent antitumors as well as antibiotic agents[…] — 2009 formsantitumors · more antitumor · most antitumor