From Halopedia, the Halo wiki
Mev-ut is the Kig-Yar equivalent of a bounty. When targeting UNSC personnel, Kig-Yar particularly go after the heads and cervical vertebrae of their victims. They are especially interested in bringing back those equipped with neural interfaces. Some Kig-Yar put out a mev-ut out on Malcolm Geffen and Vasily Beloi for killing several of their kind on Reynes.