Physical age as measured in years.
A person’s actual age, usually expressed in years or years and months.
A child’s age as measured from the birthdate, which must often be attested to by showing a birth certificate or other acceptable certificate, as on entering school. A child’s age is often used in comparisons of performance, skills, or behavior with others of the same chronological age, such as educational age or mental age.
Age of a person expressed as the period of time (e.g., months, years) that has elapsed since birth.
Age as determined by years since birth.