This is the 10345th most frequent Japanese word.
骨格
Skeleton or framework.
In this sentence, '骨格' ('kokkaku') refers to the framework or structural skeleton of the building, emphasizing its physical and architectural aspect.
この建物の骨格は非常に頑丈です。
The skeleton of this building is very sturdy.
Here, '骨格' ('kokkaku') is used to describe the physical frame or build of a person, relating to their bodily structure.
彼は骨格の整った体型を持っています。
He has a well-structured physique.
In this example, '骨格' ('kokkaku') metaphorically represents the framework or main structure of an abstract concept, such as a theory.