oncology Syllabification: (on·col·o·gy)Pronunciation: /änˈkäləjē, äNG-/Definition of oncology noun Medicine the study and treatment of tumors. Derivatives oncologicPronunciation: /ˌänkəˈläjik, ˌäNG-/ adjective oncologicalPronunciation: /-kəˈläjikəl/ adjective oncologistPronunciation: /-ˈkäləjist/ noun oncology in other Oxford dictionaries Definition of oncology in the British & World English dictionary