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

The participants first had their tumors removed sometime between 2019 and 2021. —Kaitlin Sullivan, NBC News, 19 Feb. 2025

Thankfully, his treatment has gone according to plan and his tumor has shrunk for the procedure. —Tom Mulherin, Boston Herald, 15 Feb. 2025

The remaining smaller tumors will be dealt with via radiation at a later date. —Ingrid Vasquez, People.com, 14 Feb. 2025

Her gamble paid off: by her ninth treatment session, her tumor had entirely disappeared. —Jamie Ducharme, TIME, 13 Feb. 2025

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

Rhymes for tumor

• boomer
• humor
• humour
• plumer
• rumor
• rumour
• tumour
• antitumor
• pseudotumor
• consumer
• perfumer

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