1 definition by RRRRRRAAAAACCCCCHHHHH
When there is a couple together, and one extra person there without a date, so they are 'third-wheeling' the couple.
Mary: You and Your boyfriend (Jack) go to the movies together.
Wendy: It will be boring without you though, can't you come?
Mary: Only if we invite another person so Im not a third wheeler
Wendy: It will be boring without you though, can't you come?
Mary: Only if we invite another person so Im not a third wheeler
by RRRRRRAAAAACCCCCHHHHH September 30, 2013