abnormal

1 of 2

adjective

ab·​nor·​mal (ˌ)ab-ˈnȯr-məl 

əb-

: deviating from the normal or average

a person with abnormal [=exceptional] strength

abnormal powers of concentration

often : unusual in an unwelcome or problematic way

abnormal behavior

abnormal test results

abnormally

(ˌ)ab-ˈnȯr-mə-lē 

əb-

adverb

behaving abnormally

abnormal

2 of 2

noun

: an abnormal person

Synonyms

Adjective

• unusual
• extraordinary
• exceptional
• unique
• rare
• uncommon
• odd

Examples of abnormal in a Sentence

Adjective

The results of the blood test were abnormal.

a completely abnormal school day, because half of the kids were out sick

Recent Examples on the Web

Adjective

Researchers from Copenhagen University Hospital in Denmark followed 1,200 patients at high risk for ventricular arrhythmias (abnormal heart rhythms) who already had tiny implantable cardioverter-defibrillators (ICDs) in their chests. —Angelica Stabile, FOXNews.com, 9 Sep. 2025

Unlike traditional software tools that cannot detect unusual activity if legitimate login credentials are used, hardware-level security can detect unusual access patterns—like mass file transfers or abnormal read/write activity—at the physical layer. —Camellia Chan, Forbes.com, 8 Sep. 2025

Noun

Welcome to the new abnormal. —Seth Borenstein, Anchorage Daily News, 9 Dec. 2022

There's only a new abnormal. —Faye Flam, Star Tribune, 2 Feb. 2021

Word History

Etymology

Adjective

New Latin abnormis "deviating from the average" (going back to Medieval Latin, "not conforming to rule," going back to Latin, "belonging to no school of philosophy," from ab- ab- + norma "carpenter's rule, pattern") + -al entry 1 — more at norm

Noun

noun derivative of abnormal entry 1

First Known Use

Adjective

1817, in the meaning defined above

Noun

1857, in the meaning defined above

Phrases Containing abnormal

• abnormal psychology

Rhymes for abnormal

• conformal
• informal
• lognormal
• nonformal
• subnormal
• formal
• formyl
• orthonormal
• paranormal
• supernormal

Kids Definition

abnormal

adjective

ab·​nor·​mal

(ˈ)ab-ˈnȯr-məl

: differing from the normal or average : unusual

abnormally

-mə-lē

adverb

Medical Definition

abnormal

1 of 2 adjective

ab·​nor·​mal (ˈ)ab-ˈnȯr-məl 

: deviating from the normal, average, or expected

abnormal development

results of the Pap smear were abnormal

abnormal actions departing from accepted standards of social behavior

abnormally

-mə-lē 

adverb

abnormal

2 of 2 noun

: an abnormal person