sphincter

noun

sphinc·​ter ˈsfiŋ(k)-tər 

: an annular muscle surrounding and able to contract or close a bodily opening

sphincteric

sfiŋ(k)-ˈter-ik 

adjective

Examples of sphincter in a Sentence

Recent Examples on the Web

The reflex’s afferent wiring supports this: the stimulus appears to originate in the region of the lower esophagus and stomach, and the lower esophageal sphincter relaxes simultaneously during a hiccup, which would aid in venting gas upward. —Scott Travers, Forbes.com, 22 Apr. 2026

When the time comes, when sphincters get tight, will the Wildcats cower? —Jon Wilner, San Diego Union-Tribune, 18 Mar. 2026

These compounds also relax the band of muscles called the lower esophageal sphincter (LES). —Carrie Madormo, Verywell Health, 10 Mar. 2026

At the same time, digestion slows down (hello, constipation!) and your lower esophageal sphincter relaxes, which could cause acid reflux. —Julia Ries Wexler, SELF, 9 Feb. 2026

Word History

Etymology

Late Latin, from Greek sphinktēr, literally, band, from sphingein to bind tight

First Known Use

1578, in the meaning defined above

Kids Definition

sphincter

noun

sphinc·​ter ˈsfiŋ(k)-tər 

: a ringlike muscle surrounding a body opening that is able to make the opening smaller or close it

Medical Definition

sphincter

noun

sphinc·​ter ˈsfiŋ(k)-tər 

: an annular muscle surrounding and able to contract or close a bodily opening see anal sphincter, cardiac sphincter, precapillary sphincter, pyloric sphincter

sphincteral

-t(ə-)rəl 

adjective