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

Considering that the large majority of children receive acetaminophen—one study found that 95 percent of infants are given the drug at least once in their first year of life—acetaminophen alone clearly doesn’t cause autism. —Tom Bartlett, The Atlantic, 9 Sep. 2025

Despite ongoing lawsuits, federal judges have so far found the scientific evidence linking acetaminophen use in pregnancy to autism or ADHD to be inconclusive, leading to the dismissal of several high-profile cases. —Sheryl Estrada, Fortune, 9 Sep. 2025

Using acetaminophen during pregnancy has been believed to cause neurodevelopmental disorders, such as autism, in kids. —Sherri Gordon, Parents, 9 Sep. 2025

Shares in the company that makes Tylenol — a popular brand of acetaminophen — fell 10% on the news. —Ben Smith, semafor.com, 8 Sep. 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