When it comes to describing one's greatest triumph, there are a plethora of synonyms that can be used. Some of the most commonly used words include victory, success, accomplishment, achievement, conquest, and mastery. Each of these words carries a slightly different connotation and can be used in different contexts depending on the situation. For instance, victory might be used to describe a win in a competition, whereas mastery might be used to describe the culmination of years of hard work and dedication. Regardless of the word chosen, however, all synonyms for "greatest triumph" signify a significant moment of achievement and success.