chemotherapy

American  

[kee-moh-ther-uh-pee, kem-oh-] / ˌki moʊˈθɛr ə pi, ˌkɛm oʊ- /

noun

Medicine/Medical.

1. the treatment of disease by means of chemicals that have a specific toxic effect upon the disease-producing microorganisms or that selectively destroy cancerous tissue.

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chemotherapy British  

/ kiːmə-, ˌkiːməʊˈθɛrəpɪ /

noun

1. treatment of disease, esp cancer, by means of chemical agents Compare radiotherapy

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chemotherapy Scientific  

/ kē′mō-thĕr′ə-pē /

1. The treatment of disease, especially cancer, using drugs that are destructive to malignant cells and tissues.

2. The treatment of disease using chemical agents or drugs that are selectively toxic to the causative agent of the disease, such as a microorganism.

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chemotherapy Cultural  

1. The treatment of disease with chemicals. The term chemotherapy often refers to a kind of treatment for cancer in which chemicals are administered to destroy cancer cells.

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Discover More

There are often side effects to chemotherapy, a common one being the temporary loss of hair.

Other Word Forms

• chemotherapist noun

Etymology

Origin of chemotherapy

First recorded in 1905–10; chemo- + therapy

Explanation

Chemotherapy is a common treatment for cancer. Patients who receive chemotherapy take strong anti-cancer drugs meant to kill the cancer cells. Chemotherapy is given through an IV directly into a patient's veins or in pill form. While chemotherapy is a powerful tool for keeping cancer cells from reproducing, it can often make people feel quite sick because it kills other cells as well. The word literally means "treatment of diseases by chemicals," from the German Chemotherapie and its roots, the scientific prefix chemo-, "chemical," and the Greek therapeia, "healing."

Example Sentences

Research focused on using chemotherapy and radiation to wipe out diseased bone marrow, then infusing healthy donor cells to create a new immune system capable of attacking cancer and rebuilding the body’s defenses.

From The Wall Street Journal • Apr. 19, 2026

Median overall survival was 13.2 months with daraxonrasib, which patients took orally once a day, versus 6.7 months with chemotherapy.

From Barron's • Apr. 13, 2026

Targeted therapies have already reshaped cancer care by directing drugs straight to tumors, helping reduce damage to healthy cells and easing harsh side effects linked to chemotherapy.

From Science Daily • Apr. 2, 2026

As the cancer had not spread, the father of three did not need chemotherapy or radiotherapy and was back working within six months.

From BBC • Mar. 31, 2026

And then I saw him as the adult who had drifted away, thin and frail, his face bony from the chemotherapy treatments.

From "Tuesdays with Morrie" by Mitch Albom

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