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

There are approximately 25 cases annually in the United States of very high-risk relapsed Wilm’s tumor, according to CCRF. —Mark Tatge, Forbes, 13 Dec. 2024

Meanwhile, Cotton — who recently underwent surgery to remove a benign tumor — last posted about Wood on his birthday on Instagram in October. —Daniela Avila, People.com, 13 Dec. 2024

This can result from various factors, including brain tumors, high blood pressure, head injuries, or aneurysms in the brain. —Abby Norman, Verywell Health, 12 Dec. 2024

Among the various solid tumors, 13 cases were stage 4, having spread to other organs and tissues. —Byjennifer Couzin-Frankel, science.org, 4 Dec. 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