cap: the building in Washington, D.C., in which the United States Congress meets
Word History of CAPITOL
The word capitol is pronounced the same as capital, and the two words seem to have linked meanings: the building called the Capitol is located in our nation's capital. Curiously, their origins are quite different, though both come from Latin. Capital is from capitalis, which means literally “of the head” and in later Latin came to mean “chief” or “principal.”Capitol is from the Capitolium, a hill at the center of ancient Rome that held a fortress and an important temple to the god Jupiter.