100 Words Almost Everyone Confuses and Misuses
by the Editors of the American Heritage® Dictionaries
1. A building or complex of buildings in which a state legislature meets.
2. Capitol The building in Washington DC where the Congress of the United States meets.
[Middle English Capitol, Jupiter's temple in Rome, from Old French capitole, from Latin Capitlium, after Capitlnus, Capitoline, the hill on which Jupiter's temple stood; perhaps akin to caput; see etymology at capital1.]
See Note at capital.