Sphincter \Sphinc"ter\, n. [NL., fr. ??? to bind tight.]

(Anat.) A muscle which surrounds, and by its contraction tends to close, a natural opening; as, the sphincter of the bladder.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Sphincter \Sphinc"ter\, a. (Anat.) Of, pertaining to, or designating, a sphincter; as, a sphincter muscle.

Source: Webster's Revised Unabridged Dictionary (1913)