acetaminophen

noun

acet·​amin·​o·​phen ə-ˌsē-tə-ˈmi-nə-fən How to pronounce acetaminophen (audio)
ˌa-sə-tə-
: a crystalline compound C8H9NO2 that is a hydroxy derivative of acetanilide and is used in chemical synthesis and in medicine to relieve pain and fever

Examples of acetaminophen in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The press release also said that acetaminophen is the only safe over-the-counter pain medication for pregnant women to take for fever, which can be harmful for a developing fetus. Sydney Lupkin, NPR, 29 Sep. 2025 According to medical experts, when taken as directed, traditional over-the-counter pain relievers like acetaminophen and nonsteroidal anti-inflammatory medicines (NSAIDs) can be safe and effective. Janet Loehrke, USA Today, 28 Sep. 2025 For example, mothers who take acetaminophen are more likely to also have migraines, chronic pain, fever or serious infections. CNN Money, 28 Sep. 2025 In the wake of the White House's announcement on Monday of a potential link between acetaminophen use in pregnancy and autism, the administration also unveiled the launch of the Autism Data Science Initiative (ADSI). Mary Kekatos, ABC News, 26 Sep. 2025 See All Example Sentences for acetaminophen

Word History

Etymology

acet(yl) + amino + phen(ol)

Note: Shortened from N-acetyl-p-aminophenol. Acetaminophen was introduced as a generic name roughly coincident with the introduction of the trademark preparation Tylenol, which was first marketed as "Children's Tylenol Elixir" in 1955 by McNeil Laboratories. Synthesis of the substance, as acetylamidophenol, was first reported in Berichte der Deutschen Chemischen Gesellschaft, 11. Jahrgang (Jan.-Juni, 1878), p. 232-33 (H. N. Morse, "Ueber eine neue Darstellungsmethode der Acetylamidophenole"). Its antipyretic properties were recognized by the German physician Josef von Mering in the 1893 article "Beiträge zur Kenntniss der Antipyretica" (Therapeutische Monatshefte, 7, pp. 577-87)—he also refers to it as acetylamidophenol.

First Known Use

1958, in the meaning defined above

Time Traveler
The first known use of acetaminophen was in 1958

Browse Nearby Words

Cite this Entry

“Acetaminophen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/acetaminophen. Accessed 3 Oct. 2025.

Kids Definition

acetaminophen

noun
acet·​amin·​o·​phen ə-ˌsēt-ə-ˈmin-ə-fən How to pronounce acetaminophen (audio)
: a crystalline compound used in medicine to relieve pain and fever

Medical Definition

acetaminophen

noun
acet·​amin·​o·​phen ə-ˌsēt-ə-ˈmin-ə-fən How to pronounce acetaminophen (audio) ˌas-ət- How to pronounce acetaminophen (audio)
: a crystalline compound C8H9NO2 that is a hydroxy derivative of acetanilide and is used in chemical synthesis and in medicine instead of aspirin to relieve pain and fever

called also paracetamol

see liquiprin, panadol, tylenol

More from Merriam-Webster on acetaminophen

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!