年龄

You are under age, you can't drive a car yet.

The boy seemed older than his years.

At your age you should know better.

be/look older than one's age

do not look one's age; be/look younger than one's age

age-sex structure

be well-matched in age

intelligence age

age for enlistment

hide one's age

mental age

retirement age

child-bearing age

the age of admittance; school age

lie about one's age

eligible age (for sth)

lawful/legal age

primiparous age

the age of maturity/discretion/marriage