A teenager.
The numbers between thirteen and nineteen.
The number of people at the meeting was in the teens.
The time of life between thirteen and nineteen years old; the teenage years.
She is in her teens.
The second decade of a century: the 1910s, 2010s, etc. The oneties, the tens.
(temperature, rates) The range between 10 and 19.
Although it was a scorching desert by day, temperatures could drop as low as the teens at night.