Use thousandth in a sentence. 1  coming last in a series of a thousand; 1,000th. 2  designating any of the thousand equal parts of something.
For other uses, see Brigham City (disambiguation). Brigham City is a city in Box Elder County, Utah, United States. The population was 17,899 at the 2010 census. It is the county seat of Box Elder County. It lies on the western slope of the Wellsville Mountains, a branch of the Wasatch Range at the western terminus of Box Elder Canyon.
Iron County, Utah. Iron County is a county located in the U.S. state of Utah. As of the 2010 census, the population was 46,163. Its county seat is Parowan, and the largest city is Cedar City. The county was created in 1850 and organized the following year.