expression, ichidan verb
grow taller; increase in height
Used specifically for people getting taller, often children or teenagers. The subject is the person, not the height itself.
最近、息子の背が伸びて、服が小さくなった。
Recently my son has grown taller and his clothes have become too small.
中学生のとき、一年
When I was in junior high, I grew 10 centimeters in one year.