haemangiomaPronunciation: /ˌhiːmandʒɪˈəʊmə/ (US hemangioma)Definition of haemangioma noun (plural haemangiomas or haemangiomata /-mətə/) Medicine a benign tumour of blood vessels, often forming a red birthmark. haemangioma in other Oxford dictionaries Definition of haemangioma in the US English dictionary