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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

Some previous studies have indicated risks of acetaminophen to fetal development, but others have found no link, the Journal has reported.

From The Wall Street Journal • Mar. 10, 2026

Could his trouble pronouncing acetaminophen be a phonemic paraphasic error?

From Slate • 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

The ongoing phase II trial is designed to determine whether adding fomepizole to standard acetylcysteine treatment can reduce liver damage in patients at high risk after acetaminophen overdose.

From Science Daily • Jan. 18, 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.