English Reference
Noun

tumor

n. countable
B2 Upper Intermediate US /ˈtumɝ/ tu·mor UK spelling tumors, tumour

n.a mass of extra cells that grows in or on the body. Some are harmless, but others can cause serious health problems like cancer.

n.an abnormal mass of tissue resulting from excessive cell division. It may be benign, meaning it does not spread, or malignant, indicating a cancerous growth.


SIMPLE

The doctor found a small tumor during the routine scan.

CONTEXTUAL

After the biopsy, the medical team confirmed that the tumor was benign and required no further treatment.

COMPLEX

Advances in oncology have allowed surgeons to target the tumor with extreme precision, minimizing damage to the surrounding healthy tissue during the procedure.

Usage

Commonly modified by the adjectives 'benign' or 'malignant' to indicate the level of health risk.

It allowed them to safely remove as much of the tumour as possible.

BBC News· 26 Aug 2026

Her doctor could not confirm whether it was related to the tumour or not.

The Guardian· 27 Aug 2026

From Middle English tumour, from Old French tumour, from Latin tumor (“swelling”), from tumeō (“bulge, swell”, verb), from Proto-Italic tumēō, from Proto-Indo-European tewh₂- (“to swell”). Related to English thumb.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin ine-pro *tewh₂-
Level B2 · Upper Intermediate
Frequency Frequent
Updated