Osage, a language of the Dhegiha branch of the Siouan family, was spoken until recently by tribal members in northeastern Oklahoma. No longer in daily use, it was in danger of extinction. Carolyn Quintero, a linguist raised in Osage County, worked with the last few fluent speakers of the language to preserve the sounds and textures of their complex speech. Compiled after painstaking work with these tribal elders, her Osage Dictionary is the definitive...