oncologist
Americannoun
Other Word Forms
Noun Inflected Forms
Explanation
An oncologist is a doctor who specializes in diagnosing and treating different forms of cancer. Hearing that a friend or family member has to visit an oncologist is never good news. Oncology is the medical treatment of cancer, and an oncologist is someone who has trained to practice oncology. Cancer is a disease that involves the abnormal growth of normal cells into masses, or tumors, and the word oncologist includes the prefix onco-, which is used in medical words to mean "tumor." It stems from the Greek root onkos, or "mass."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Dr Jeffrey Rubasingham, a consultant clinical oncologist, was one of the first to use the new approach at the hospital in King's Lynn.
From BBC • Jun. 18, 2026
As a gastrointestinal oncologist and researcher specializing in early-phase clinical trials, I have seen the critical need for more effective therapies for patients with pancreatic cancer.
From Science Daily • Jun. 4, 2026
One medical oncologist in South Carolina, for example, took to social media to report that insurance company Humana was denying his lung cancer patient Keytruda.
From Salon • May 15, 2026
Ezekiel J. Emanuel is an oncologist, bioethicist and health-policy expert.
From MarketWatch • May 13, 2026
They brought in a specialist called a radiation oncologist to talk Baba into getting radiation treatment.
From "The Kite Runner" by Khaled Hosseini
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
