sphinc‧ter /ˈsfɪŋktə $ -ər/
noun [countable] medical[
Date: 1500-1600;
Language: Late Latin;
Origin: Greek, from sphingein 'to tie tightly']
a muscle that surrounds an opening in your body, and can become tight in order to close the opening
[TahlilGaran] Dictionary of Contemporary English ▲