a territory established by the Mormons in 1849 as a proposed state of the Union: was refused admission to the Union by Congress and incorporated in the newly organized Territory of Utah 1850.
Des·er·et (děz'ə-rět') An area proposed by the Mormons in 1849 as an independent state or a state of the Union. Deseret would have included much of the southwest United States, with a capital at Salt Lake City. Congress refused to recognize the provisional state and created the Utah Territory in 1850.