haemangiomaEnglishOxford Dictionary of Englishhaemangioma /ˌhiːmandʒiˈəʊmə / (US English hemangioma) ▸ noun (plural haemangiomas)(plural or haemangiomata /ˌhiːmandʒɪˈəʊmətə/) Medicine a benign tumour of blood vessels, often forming a red birthmark.