When the hairline of a person is so low that their forehead becomes reclassified a "threehead". This also suggests that their forehead is only about three finger widths high.
by hidispenser January 25, 2005
When three people have oral sex together in a circle at once.
Person A goes down on Person B, who goes down on Person C, who in turn goes down on Person A.
Person A goes down on Person B, who goes down on Person C, who in turn goes down on Person A.
by ajwfs March 24, 2008
by lexi666 May 29, 2020