a building occupied by a state legislature
"The protesters gathered outside the capitol to demand changes to the new education bill."
the government building in Washington where the United States Senate and the House of Representatives meet
"Tourists gathered outside the capitol to witness the swearing-in ceremony of the new Congress."
Any building or complex of buildings in which a legislature meets.
"The delegation arrived at the capitol to witness the opening session of the state legislature."
In plain English: A capitol is the building where a state government meets and makes laws for that specific area.
"The state capitol building stands proudly in the center of downtown."
Usage: Use capitol to refer specifically to the physical building where a state or local legislative body convenes, distinguishing it from Capitol with a capital C, which denotes the United States Congress building in Washington, D.C. Avoid using this term for any generic meeting hall unless it houses an official legislature.
The temple of Jupiter on the Capitoline Hill in ancient Rome.
"The ruins of the capitol still stand as a reminder of ancient Roman power atop the Capitoline Hill."
The word comes from the Latin Capitōlium, which originally referred to the Capitoline Hill in Rome or any similar citadel. It is derived from caput, meaning "head," and entered English through Old French and Anglo-Norman.