noun
a ring-like muscle that normally maintains constriction of a natural body passage or orifice and that relaxes as required by normal physiological functioning
-
The sphincter muscle plays a crucial role in controlling the release of waste from the body.
-
I heard that if you have a weak sphincter, you might have trouble holding in gas.
-
Dude, I think I strained my sphincter trying to lift that heavy box.
-
His sphincter tightened with fear as he approached the edge of the cliff.