capitol

This term refers specifically to the physical structure of a government building. It is frequently confused with "capital," which refers to the city that serves as the seat of government or a financial asset. While a capital city may contain a capitol building, the two are not interchangeable.

When referring to the specific building in Washington, D.C., the word is typically capitalized as a proper noun. In general references to state-level legislative buildings, it remains lowercase unless part of a formal name.