# pathological

/ˌpæθəˈɫɑdʒɪkəɫ/ (US) · /pˌæθəlˈɒdʒɪkəl/ (UK)

Source: https://englishreference.com/word/pathological
Updated: 2026-08-08

## Senses

### 1. medical/disease

adjective · CEFR C1 · Technical

relating to a physical or mental disease.

For teachers: pertaining to pathology; caused by or involving a physical or mental disorder.

- The doctor examined the pathological changes in the patient's lung tissue.
- The biopsy revealed pathological abnormalities that were inconsistent with a simple viral infection, prompting further diagnostic testing.

Usage: In medical contexts, it is the opposite of 'physiological', which refers to normal body functions.

### 3. mathematics/computing

adjective · CEFR C2 · Technical · Academic

describing a problem or case that is very strange and does not follow normal rules.

For teachers: describing a structure or case that violates standard intuition or behaves poorly under typical algorithms.

- The software crashed because it couldn't handle a pathological case in the data.
- The function was considered pathological because it was continuous everywhere but differentiable nowhere, defying the expectations of early calculus students.

Usage: Often used to describe 'edge cases' that break a system or theory.

## Examples

- He is a pathological liar who cannot tell the truth.
- The doctor ordered more tests to determine if the tissue growth was pathological or benign.
- In mathematical analysis, a pathological function is one whose properties are considered exceptionally atypical or counterintuitive, often serving as a counterexample to more general theories.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.