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acetaminophen

American  
[uh-see-tuh-min-uh-fuhn] / əˌsi təˈmɪn ə fən /

noun

Pharmacology.

  1. a crystalline substance, C 8 H 9 NO 2 , used as a headache and pain reliever and to reduce fever.

acetaminophen Scientific  
/ ə-sē′tə-mĭn′ə-fən,ăs′ə- /

  1. A crystalline compound used in medicine to relieve pain and reduce fever. Chemical formula: C 8 H 9 NO 2.

Etymology

Origin of acetaminophen

First recorded in 1955–60; acet- + amino- + phen(ol)

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Meanwhile professional societies representing obstetricians continue to say pregnant women should use acetaminophen to treat pain and fever.

From The Wall Street Journal • Mar. 10, 2026

Could his trouble pronouncing acetaminophen be a phonemic paraphasic error?

From Slate • Jan. 26, 2026

The American College of Obstetricians and Gynecologists says acetaminophen is safe to use during pregnancy.

From The Wall Street Journal • Jan. 26, 2026

The researchers hope this thorough review will help ease lingering doubts about using acetaminophen during pregnancy.

From Science Daily • Jan. 19, 2026

In these sibling comparison studies, one child was exposed to acetaminophen during pregnancy while another was not.

From Science Daily • Jan. 19, 2026

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.