English Reference
adjective · noun

abnormal

adj. · n.
US /æbˈnɔɹməɫ/ UK /ɐbnˈɔːməl/ ab·nor·mal UK spelling abnormals

  1. 01 B2 Upper Intermediate

    adj.different from what is normal or expected, especially in a way that is not good.

    adj.deviating from a standard, rule, or typical pattern; often used in technical or medical contexts to describe results outside the expected range.

    Simple

    The doctor said the test results were abnormal and ordered more scans.

    In context

    The meteorological station recorded abnormal temperature fluctuations throughout the month, suggesting a significant shift in regional climate patterns.

    Usage

    Often used to describe data, physical conditions, or weather patterns.

  2. 02 C1 Advanced Formal

    adj.behaving in a way that is not considered social or healthy by most people.

    adj.pertaining to behaviour that deviates from social norms or accepted standards of psychological health.

    Simple

    The suspect showed abnormal behaviour during the police interview.

    In context

    Psychologists noted that the subject's abnormal reactions to social stimuli were consistent with a rare neurological condition.

    Teacher's tip

    In modern social contexts, this can sound judgmental; 'atypical' or 'unconventional' are often softer alternatives.

  3. 03 C2 Proficiency FormalArchaic

    n.a person or thing that is not normal.

    n.an individual or object that deviates from the norm; used as a substantive noun.

    Simple

    In this group of healthy plants, this stunted one is an abnormal.

    In context

    The researcher categorised the outliers as abnormals to be studied separately from the control group.

    Usage

    Rarely used as a noun in modern English; usually functions as an adjective.

That helps you learn what looks and feels normal for you, making it easier to notice any abnormal changes.

BBC News· 12 Aug 2026

A few days later, I received a follow-up text to say there were no abnormal skin changes that required treatment.

BBC News· 8 Aug 2026

From ab- + normal. First attested in 1835, replacing the earlier anormal and even earlier abnormous, from Latin abnormis (“departing from normal”), from either ab- (“away from”) + norma (“rule, norm”), or Ancient Greek ἀνώμαλος (anṓmalos).

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

This entry
Origin Ancient Greek ἀνώμαλος
Level B2 · Upper Intermediate
Frequency Frequent
Updated