What is triumph? What is triumph? To be victorious or successful; win.To rejoice over a success or victory; exult.To receive honors upon return from a victory in ancient Rome. Used of a general. The fact of being victorious; victory or conquest. See Synonyms at victory.A noteworthy or spectacular success.Exultation or rejoicing over victory or success.A public celebration in ancient Rome to welcome a returning victorious commander and his army.Obsolete A public celebration or spectacular pageant.