- The definition of a teenager is a person who is between ages 13 and 19, all numbers ending in the suffix -teen.
An example of a teenager is someone who just has their thirteenth birthday.
- (countable) Literally, a person from thirteen to nineteen, an adolescent.
Sometimes only refers up to the legal minor limit in many countries of eighteen years old, or sometimes only refers up to the point of high school graduation. In the earlier years, sometimes referred to as a youth; in later years, sometimes referred to as a young adult.