A competitive or non-competitive event, where participants attempt to complete without stopping in three successive events, hot or dry sauna, whirlpool or hot tub, and steam bath.
Lewis I do not want to do the triathlon today, I will beat you in a tribathlon instead!
by Ben V March 21, 2006
A very long session of tribadism, the lesbian genito-genital sex act.
We came over and over again; it was a real tribathlon.
by Skek January 14, 2006