pathological

American  

[path-uh-loj-i-kuhl] / ˌpæθ əˈlɒdʒ ɪ kəl /

Also pathologic

adjective

1. of or relating to pathology, or the science or study of diseases and their causes.

   Research into the pathological origins of alcoholism is ongoing.

2. caused by, indicative of, or involving disease.

   Her white blood cell count had fallen to a pathological level.

3. caused by or evidencing a mentally disturbed condition.

   He is a pathological hoarder.

   They show a pathological lack of concern for the suffering of others.

4. dealing with diseases.

   The neurologist kept a pathological casebook from her practice as a source of examples for lectures.

5. Mathematics. designating a phenomenon or object, such as a function, that is logically and correctly defined but has counterintuitive or paradoxical properties.

6. Computers. relating to or producing a failed outcome or one that is contrary to what was intended or expected.

   This is just an example of what happens when the algorithm encounters pathological data.

   A pathological input shouldn't break the algorithm.

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pathological British  

/ ˌpæθəˈlɒdʒɪkəl /

adjective

1. of or relating to pathology

2. relating to, involving, or caused by disease

3. informal compulsively motivated

   a pathological liar

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Other Word Forms

• nonpathologic
  adjective
• nonpathological
  adjective
• nonpathologically
  adverb
• pathologically
  adverb
• postpathologic
  adjective
• postpathological
  adjective
• semipathologic
  adjective
• semipathological
  adjective
• semipathologically
  adverb
• unpathological
  adjective
• unpathologically
  adverb

Etymology

Origin of pathological

First recorded in 1680–90; from Greek pathologik(ós) ( see pathology, -ic) + -al ¹

Explanation

If something is caused by a physical or mental disease, it is pathological. Someone with a pathological compulsion for cleanliness might scrub the floors for hours every night. Pathological comes from a Greek word, pathologikos, which means “treating of diseases” — pathos means "suffering." Anyone who studies or works with diseases, from their causes to their symptoms, identifies how the disease affects its victims, in other words, its pathological effects. Remember that this is a medical distinction. If a person has, for example, obsessive-compulsive disorder, his or her repetitive actions are pathological.

Example Sentences

As a result, Prof Voon says, friends or family can regard the change in behaviour as generosity or extravagance - rather than anything pathological - and so it continues.

From BBC • May 1, 2026

The intellectual class has never been immune to the pathological American conviction that history is bunk.

From Salon • Mar. 8, 2026

Then there’s the pathological terror of holding an actual opinion.

From The Wall Street Journal • Mar. 5, 2026

D'Alessandro notes potential relevance for exercise physiology and for pathological hypoxia after traumatic injury.

From Science Daily • Feb. 21, 2026

And yet what Jimmy had felt for her was beyond normal love; it was passion—a passion that was in part pathological.

From "In Cold Blood" by Truman Capote