This is the 5124th most frequent Japanese word.
身長
Height.
Here, '身長' is used to explicitly denote the physical height of a person.
彼の身長は180センチです。
His height is 180 cm.
In this sentence, '身長' is used comparatively to describe relative height differences.
私は兄よりも身長が高いです。
I am taller than my older brother.
While less common, '身長' here is contemplated in a figurative sense relating health to height maintenance.