leading figure; prominent person; bigwig
Refers to a person who is a central, influential, or highly respected figure in a field, organization, or community.
He is known as a leading figure in the industry.
地元の大立者たちが集まって会議を開いた。
The prominent local figures gathered and held a meeting.
star actor; leading performer
Specifically used for the top actor or star performer in a theatrical troupe or similar performing group.
その劇団の大立者は、毎回公演の主役を務める。
The star actor of that troupe plays the lead role in every performance.