adenocarcinomaPronunciation: /ˌadɪnəʊˌkɑːsɪˈnəʊmə/Definition of adenocarcinoma noun (plural adenocarcinomas or adenocarcinomata /-mətə/) Medicine a malignant tumour formed from glandular structures in epithelial tissue. adenocarcinoma in other Oxford dictionaries Definition of adenocarcinoma in the US English dictionary