a billion

Adj.	1.	a billion - denoting a quantity consisting of one million million items or units in Great Britain billion Great Britain, UK, United Kingdom, United Kingdom of Great Britain and Northern Ireland, Britain, GB - a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland cardinal - being or denoting a numerical quantity but not order; "cardinal numbers"
	2.	a billion - denoting a quantity consisting of one thousand million items or units in the United States billion U.S.A., United States, United States of America, US, USA, America, U.S. - North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776 cardinal - being or denoting a numerical quantity but not order; "cardinal numbers"

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