atypical

Etymology

It is formed from English a- + typical, with the prefix meaning "not".^{[2][3][4][5][6]} Collins also records the form atypic.^[7][6]

Earliest recorded meaning

Not typical, not conforming to the usual type: Merriam-Webster dates it to 1845,^[5] Etymonline to 1847, in the sense "having no distinct or typical character".^[2] The OED's first quotation is from before 1883, in C. H. Fagge's Principles and Practice of Medicine,^[3] and Dictionary.com dates it to 1880–85.^[6]

Semantic evolution

The word has kept its general sense, unlike the type or irregular, and is often used of abnormal behaviour or symptoms.^[5][3] In medicine it was applied to a class of antipsychotic drugs.^[5] Since 1988 atypical has also been a noun for such a drug.^[5]

Timeline

• 1845 – not typical, unlike the type.^[5][2]
• 1988 – noun, an atypical antipsychotic drug.^[5]

Meanings

Adjective

1. Not typical; not conforming to the usual type; irregular or abnormal: The warm spell was atypical for February.^[5][7][3]
2. (medicine) Of an antipsychotic drug, belonging to the newer class with fewer side effects on movement.^[5]

Noun

1. (medicine) An atypical antipsychotic drug.^[5]

Word family

• atypicality
• atypically

Related words

• typical
• type

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
4. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ a b c d e f g h i j Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins