heyday
n. countablen. the period of time when someone or something is most successful, popular, or powerful. You use this to talk about the 'golden age' of a person's career or a specific era.
n. the period of greatest success, popularity, or vigour. Often used to describe the peak of a historical era, a career, or a specific technology.
In its heyday, the city was a major center for trade.
During the heyday of silent film, actors relied entirely on physical expression to convey emotion.
The crumbling ruins serve as a stark reminder of the empire's former glory during its 12th-century heyday, when its influence stretched across three continents.
Late 16th century, from earlier heyda (1520s), as exclamation – compare hey, hei. Sense “period of success, vigor” is a respelling as heyday based on unrelated day (as “period of time”) – compare day in the sun.
Usually used in the singular, often following the preposition 'in' ('in its heyday').