His defining moment was when he showed his teacher how to multiply mixed fractions.
We live at a defining moment for humanity, as the compounding effects of technology and civilization reach an inflection point.
Since dance is incorporated into tribal rituals, it is often a defining moment when it comes to gender roles.
For the 500,000 fans that attended Woodstock, it was the defining moment of the hippie movement - the moment in the sun for the peace and love generation.
During the first season of the show, Giudice gained a reputation for lavish spending and over the top fashion, but her real defining moment came during the final episode of the first season.