The word "建筑" is formed through the combination of two characters, each carrying a closely related core meaning. The first character, "建", primarily means "to construct" or "to build", focusing on the act of establishment. It is paired with "筑", which means "to build" as well, but with a nuance of the physical act of constructing, such as laying foundations or assembling materials. Together, they create a composite idea where "建" contributes the concept of initiating and erecting, while "筑" reinforces the hands-on, tangible process of construction, resulting in a complete term that encompasses both the action of building and the built structures themselves.