The word "heyday" refers to a time in someone's life when they are at their most successful or popular. It's often used to describe a person's peak performance or achievement.
When we talk about someone's heyday, we're usually thinking about a moment in their career that stands out as particularly great. For instance, if you ask an old musician what his heyday was like, he might tell you about the time he released his most successful album or performed at a sold-out concert. People often remember and look back on their heyday with nostalgia, remembering how they felt confident and on top of their game.
A period of success, popularity, or power; prime.
Example: The early twentieth century was the heyday of the steam locomotive.
