atypical

adjective

atyp·​i·​cal (ˌ)ā-ˈti-pi-kəl 

1

: not typical : irregular, unusual

an atypical form of a disease

atypical weather for this area

2

medical : relating to or being an antipsychotic drug (such as risperidone) that tends to produce fewer adverse side effects on movement (such as dyskinesia) than previously used antipsychotic drugs (such as haloperidol)

Atypical antipsychotics work more precisely, manipulating both dopamine and serotonin and suppressing symptoms without causing so many associated problems.

—Jeffrey Kluger

atypicality

ˌā-ˌti-pə-ˈka-lə-tē 

noun

plural atypicalities

atypically

(ˌ)ā-ˈti-pi-k(ə-)lē 

adverb

Synonyms

• unusual
• extraordinary
• exceptional
• unique
• abnormal
• rare
• uncommon

Examples of atypical in a Sentence

the postal service delivered the package with atypical speed

since that's an atypical response for an infant, you might want to have her hearing tested

Recent Examples on the Web

The Supreme Court’s 6-3 decision concludes a particularly contentious term with Trump, punctuated by Chief Justice John Roberts issuing an atypical statement in March. —Naomi Lim, The Washington Examiner, 28 June 2025

Authority was centralized in a new reporting group led by Chapek lieutenant Kareem Daniel, who alongside his mentor, exerted atypical control over content decisions. —Winston Cho, HollywoodReporter, 27 June 2025

His atypical path to the big time is not just a quirk of his story, a curious little footnote. —Jack Lang, New York Times, 27 June 2025

The researchers identified a molecule, atypical protein kinase C (aPKC), that became overactive in response to the high-fat and high-sugar intake characteristic of a WD. —New Atlas, 21 June 2025

Word History

Etymology

see typical

First Known Use

1845, in the meaning defined at sense 1

Phrases Containing atypical

• primary atypical pneumonia

Rhymes for atypical

• untypical
• prototypical
• stereotypical
• typical

Kids Definition

atypical

adjective

atyp·​i·​cal (ˈ)ā-ˈtip-i-kəl 

: not typical : irregular

atypically

-i-k(ə-)lē 

adverb

Medical Definition

atypical

1 of 2 adjective

atyp·​i·​cal (ˈ)ā-ˈtip-i-kəl 

1

: not typical : not like the usual or normal type

The procedure, ductal lavage, washes cells from the milk ducts, where 95 percent of breast cancers start. Tests can then be performed to look for atypical or abnormal cells.

—Judith Groch, The New York Times

The results of treatment of patients with gallstones are less successful in individuals with atypical pain patterns or painless dyspepsia …

—The Journal of the American Medical Association

In some patients with atypical dysgenesis, the smear may show slight proliferation.

—George L Wied et al., Compendium on Diagnostic Cytology

2

: relating to or being an antipsychotic drug (such as aripiprazole and risperidone) that tends to produce fewer adverse side effects on movement (such as akathisia or dyskinesia) than previously used antipsychotic drugs (such as haloperidol)

Atypical antipsychotics work more precisely, manipulating both dopamine and serotonin and suppressing symptoms without causing so many associated problems.

—Jeffrey Kluger, Time

Although studies indicated that the atypical drugs are similar to the conventional drugs in reducing psychotic symptoms and produce few neurologic effects, the evidence of their superior efficacy has been neither consistent nor robust …

—Jeffrey A. Lieberman et al., The New England Journal of Medicine

atypically

(ˈ)ā-ˈtip-i-k(ə-)lē 

adverb

Atypically depressed patients often show a different clinical picture from those with "classical" major depression.

—Ronald Pies, The New York Times

atypical

2 of 2 noun

: an atypical antipsychotic drug (see atypical entry 1 sense 2)

Her 24-year-old daughter, diagnosed with schizophrenia in 1993, had problems with two types of atypicals before a third proved successful.

—Stephaan Harris, USA Today