成年 (chéng nián): เพื่อเติบโตเป็นผู้ใหญ่

This giant panda has just turned three years old and is considered an adult; it can now leave its mother and live on its own.

This kind of bird keeps following its parents to find food before it reaches adulthood; only after becoming an adult does it fly far away to establish its own territory.

The lawyer reminded us that this contract must be signed personally by the children who have already reached adulthood; the parents cannot sign on their behalf.