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

Research on the relationship between acetaminophen and Autism Spectrum Disorder has varied, but many physicians say evidence does not support a causal relationship. —Molly Parks, The Washington Examiner, 28 Oct. 2025

In addition to the allegations that the companies hid the risks of taking acetaminophen, Paxton’s lawsuit also alleges that Johnson & Johnson sought to evade liability for its actions by spinning off Kenvue. —Solcyré Burga, Time, 28 Oct. 2025

In a statement, a spokeswoman for Kenvue reiterated that acetaminophen is the safest pain reliever option for pregnant women. —Ciara McCarthy, Fort Worth Star-Telegram, 28 Oct. 2025

Dozens of people have sued Johnson & Johnson, generic manufacturers and major retailers alleging developmental injuries such as autism and ADHD due to mothers' prenatal use of acetaminophen. —N'dea Yancey-Bragg, USA Today, 28 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