acetaminophen

noun

acet·​amin·​o·​phen ə-ˌsē-tə-ˈmi-nə-fən 

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

Medications may include NSAIDs, acetaminophen or other non-opioid drugs. —Jacqueline Howard, CNN Money, 7 Oct. 2025

During the study period, patients were only allowed to use acetaminophen as needed but could not use other pain relievers. —Tom Gavin, EverydayHealth.com, 3 Oct. 2025

When looking at individual children, the researchers found up to a 5% increase in autism for those exposed to acetaminophen during pregnancy. —Tami S. Rowen, The Conversation, 3 Oct. 2025

Between 40% and 65% of pregnant women report using acetaminophen – the active ingredient in Tylenol – at some point during their pregnancy in large surveys, according to the Society for Maternal-Fetal Medicine. —Sam Woodward, USA Today, 3 Oct. 2025

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

Kids Definition

acetaminophen

noun

acet·​amin·​o·​phen ə-ˌsēt-ə-ˈmin-ə-fən 

: 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  ˌas-ət- 

: 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