tumor

noun

tu·​mor ˈtü-mər 

ˈtyü-

1

: an abnormal benign or malignant new growth of tissue that possesses no physiological function and arises from uncontrolled usually rapid cellular proliferation

called also neoplasm

2

: a swollen or distended part

… houses that bulged with the tumors and warts of … ornamental architecture …

—W. A. White

tumoral

ˈtü-mə-rəl 

ˈtyü-

adjective

tumorlike

ˈtü-mər-ˌlīk 

ˈtyü-

adjective

Synonyms

• excrescence
• excrescency
• growth
• lump
• neoplasm

Examples of tumor in a Sentence

the scan showed a small tumor in her abdomen

Recent Examples on the Web

Prior to his death, Eddie reportedly became addicted to prescribed steroid pills to relieve swelling after a surgery to remove a brain tumor. —Angel Saunders, People.com, 18 Oct. 2024

The cell line in this image originally came from a mouse brain tumor, but here these cells serve as a general model for any brain cell. —Eva Amsen, Forbes, 17 Oct. 2024

But doctors were unable to remove the tumor entirely, his mother told CNN last week. —Jomana Karadsheh, CNN, 16 Oct. 2024

Before that, doctors performed Gamma Knife surgery to remove a brain tumor, and gave Eddie steroid pills to combat swelling. —Brian Hiatt, Rolling Stone, 15 Oct. 2024

Word History

Etymology

Middle English tumour, from Latin tumor, from tumēre

First Known Use

15th century, in the meaning defined at sense 2

Phrases Containing tumor

• anti-tumor
• tumor load
• tumor necrosis factor
• tumor suppressor gene

Kids Definition

tumor

noun

tu·​mor ˈt(y)ü-mər 

: an abnormal mass of tissue that arises from normal tissue cells and serves no useful purpose in the body

tumorous

ˈt(y)üm-(ə-)rəs

adjective

Medical Definition

tumor

noun

tu·​mor

variants or chiefly British tumour

ˈt(y)ü-mər 

: an abnormal benign or malignant new growth of tissue that possesses no physiological function and arises from uncontrolled usually rapid cellular proliferation see cancer sense 1, carcinoma, sarcoma

tumorlike

-ˌlīk 

adjective