An adult, especially as contrasted with a child.

बड़ा व्यक्ति

English Usage: "When I was a kid, I couldn't wait to be a grown up."

Hindi Usage: "जब मैं बच्चा था, तो मैं बड़ा व्यक्ति बनने का इंतज़ार नहीं कर सकता था।"

Mature or fully developed.

परिपक्व

English Usage: "He is a grown up man who takes responsibility for his actions."

Hindi Usage: "वह एक परिपक्व आदमी है जो अपने कार्यों की ज़िम्मेदारी लेता है।"