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

At Rani’s intake of Tylenol-3, Tariq ought to have been consuming less than a milligram of acetaminophen per day—around half a per cent of what an infant of his size might receive as a standard treatment for pain. —Ben Taub, New Yorker, 26 Jan. 2026

Using the common painkiller acetaminophen during pregnancy is not linked to neurodevelopmental disorders in children, according to a study published in the Lancet. —Bloomberg News, Boston Herald, 17 Jan. 2026

Skip acetaminophen after drinking. —Sarah Jividen, Verywell Health, 17 Jan. 2026

The researchers found no evidence that acetaminophen use during pregnancy increases the risk of autism, attention-deficit/hyperactivity disorder or intellectual disability among children. —Jacqueline Howard, CNN Money, 16 Jan. 2026

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