Definition of tumor in English:


Syllabification: tu·mor
Pronunciation: /ˈt(y)o͞omər
(British tumour)


  • 1A swelling of a part of the body, generally without inflammation, caused by an abnormal growth of tissue, whether benign or malignant.
    More example sentences
    • One of the commonest reasons for undertaking a biopsy is to establish whether a tumour is malignant or benign.
    • Both benign and malignant tumors showed ulceration of the overlying mucosa.
    • Malignant brain tumors grow and spread into neighboring tissues rapidly.
    cancerous growth, malignant growth, cancer, malignancy; lump, growth, swelling, fibroid; Medicine carcinoma, sarcoma
  • 1.1 archaic A swelling of any kind.



Pronunciation: /-mərəs/
More example sentences
  • Neither ductal nor lobular carcinoma in situ were found in multiple sections of both tumorous and nontumorous breast tissue.
  • A 19-year-old man presented with a tumorous swelling of the left 10th rib of approximately 1 year's duration.
  • Hamartoma is a tumorous lesion that consists of anomalously arranged tissues that are components of the normal structure of origin.


late Middle English: from Latin tumor, from tumere 'to swell'.

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