by Dave Butler May 31, 2006
A ringlike muscle that normally maintains constriction of a body passage or orifice and that relaxes as required by normal physiological functioning.
by mastershake211 March 5, 2006
Circular muscle in the anus; can be developed in gay anal sex receivers to clamp down on the penis and give pleasure to the giver, often making them ejaculate, depending on the skill of the receiver.
Peter Goesinya always like to fuck Chuck because Chuck's sphincter muscle had been well trained and was always used at just the right time.
by Richard Black April 12, 2005
by Damien Hogg December 5, 2006
"4chan is the sphincter of the internet "
by black thunder 99 February 27, 2016
by Chip Assman April 29, 2003