What does malignant mean?
Malignant is an adjective meaning harmful, dangerous, or deliberately hostile. Its most important technical use is in medicine, where a malignant tumor is cancerous and may invade nearby tissue or spread to other parts of the body. This contrasts with a benign growth, which is generally not cancerous and is often harmless. In everyday and legal contexts, malignant can describe a person, motive, or influence as spiteful, hostile, or intended to cause damage, as in “malignant intent.” The word carries a strongly negative connotation and is more forceful than general terms such as harmful. Its history comes through the Latin malignus, meaning evil or harmful in character, which reflects both the word’s medical associations and its older figurative sense. Today, it is especially useful when discussing cancer, disease progression, or conduct motivated by hostility.
adjectiveHarmful or destructive to health or well-being; in medical contexts, indicating or involving cancer or the tendency to become cancerous. The word can also describe a person or influence as spiteful, hostile, or actively wishing harm.
- Harmful or destructive to health or well-being.
- In medicine, indicating or involving cancer or the tendency to become cancerous.
- Characterized by hostility, spite, or a desire to cause harm.
"The doctor explained that the tumor was malignant and required prompt treatment."
"The test results revealed a malignant lesion that required immediate attention."
"She refused to believe that the accusation was merely a malignant attempt to damage his reputation."
From Latin for “evil,” “malignant” began as a moral judgment before becoming one of medicine’s most consequential descriptions of a tumor.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does malignant come from?
The word comes from Latin malignus, meaning “evil,” “malicious,” or “harmful,” a development that reflects its longstanding figurative sense. English borrowed it in the late 16th or early 17th century, initially especially in the sense of harmful or malign in character. Its medical use for cancerous disease developed later and became established in the 18th and 19th centuries. Related English forms include malignity and malignancy, both continuing the same Latin root.
Related word forms
How malignant is actually used
In medical writing, the term is technical and specifically contrasts with benign. In general use, it often describes hostile or spiteful behavior and can sound more dramatic than simply harmful.
Easily confused with malignant
A benign growth or condition is not cancerous and usually does not spread or cause serious harm, whereas a malignant one is cancerous or otherwise seriously damaging.