the.com/tumour

means An abnormal mass of tissue that forms when cells multiply beyond the body's normal controls, either harmless (benign) or dangerous (malignant).

from From Latin tumor, 'a swelling,' rooted in the verb tumere, 'to swell up' — the same root that gives us 'tumid' and 'tumescent.' For centuries the word simply described any swelling under the skin, lump or bruise alike; medicine later narrowed it to mean a growth of abnormal tissue, the swelling now coming from cells rather than fluid or inflammation.