1. periods of greatest success, popularity, or vigor; prime times
Usage: plural of heyday

Examples

• The 1960s were the heydays of rock and roll music.
• During the heydays of the Roman Empire, trade flourished across Europe.
• Many actors look back fondly on their heydays in Hollywood.
• The company’s heydays were in the 1980s when profits soared.
• These old photographs capture the heydays of our small town.
• The heydays of steam locomotives ended with the rise of diesel trains.