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

Tylenol is a brand name for the pain reliever acetaminophen. —Jacqueline Howard, CNN Money, 12 Sep. 2025

Shares in the company that makes Tylenol — a popular brand of acetaminophen — fell 10% on the news. —Jeronimo Gonzalez, semafor.com, 10 Sep. 2025

Packages of acetaminophen on a shelf at Jack's Pharmacy on January 21, 2020, in San Anselmo, California. —Hollie Silverman, MSNBC Newsweek, 10 Sep. 2025

Since then, a handful of experts, including the dean of Harvard’s school of public health, have published papers suggesting an association between prenatal use of acetaminophen and neurodevelopmental disorders, including autism. —Tom Bartlett, The Atlantic, 9 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