person who achieves greatness; person who perfects something
Refers to someone who has brought a field, theory, or art to full fruition or achieved personal mastery. Often used in formal or literary contexts.
He is regarded as the person who perfected modern Japanese architecture.
She is internationally known as the person who brought that theory to completion.
Compound of 大成 (たいせい, 'great achievement, completion') and 者 (しゃ, 'person').