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chemotherapy

n.
US //ˌkimoʊˈθɛɹəpi// UK //kˌiːməʊθˈɛɹəpi// chemo·ther·apy
  1. 1 cancer treatment (n.)
    B2 Upper Intermediate Technical Medicine

    a medical treatment using powerful drugs to kill cancer cells or stop them from growing.

    the use of cytotoxic drugs to destroy or inhibit the growth of malignant cells in the treatment of cancer.

    Example

    She felt very tired after her second round of chemotherapy at the hospital.

    Example

    The oncologist recommended a combination of surgery and chemotherapy to ensure that any remaining microscopic cancer cells were eradicated.

    Usage

    Often shortened to 'chemo' in informal conversation; usually functions as an uncountable noun but can be countable when referring to specific regimens.
    • chemo
    • cytotoxic therapy
  2. 2 general chemical treatment (n.)
    C2 Proficiency Technical Formal Medicine

    any treatment for a disease that uses chemical substances.

    the treatment of disease by means of chemical substances that have a specific toxic effect upon the microorganisms or other causes of the disease.

    Example

    In its broadest sense, chemotherapy includes the use of antibiotics to fight infections.

    Example

    The historical development of chemotherapy began with the search for 'magic bullets' that could target specific pathogens without harming the host organism.

    Usage

    In modern contexts, this broader meaning is rare and almost exclusively found in academic or historical medical texts.
    • chemical therapy
Origin

From chemo- + therapy.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Related words

Last updated June 20, 2026