Where does the name Nacogdoches come from?

Here's an answer from the Handbook of Texas Online:

NACOGDOCHE INDIANS. The Nacogdoche (Nacadocheeto, Nacodissy, Nacodochito, Nagodoche, Nasahossoz, Naugdoche, Nocodosh) Indians, a Caddoan tribe of the Hasinai group in eastern Texas, lived in the vicinity of present Nacogdoches in the seventeenth and eighteenth centuries. In 1716 the Nuestra Señora de Guadalupe de los Nacogdoches Mission was established in the principal Nacogdoche settlement and was intermittently maintained until 1773. The tribe was greatly reduced by disease and warfare by 1800. Although many Nacogdoche Indians seem to have been absorbed by the population of the Spanish settlement established at Nacogdoches in 1779, others lost their identity among other nearby Hasinai tribes, especially the Hainai and Anadarko Indians, who moved westward to the Brazos River shortly after the Texas Revolutionqv and were eventually taken to Indian Territory, now Oklahoma. Descendants of the Nacogdoche Indians are probably included in these Hasinai survivors, who today live in Caddo County, Oklahoma.

More about the Hasinai Indians:

HASINAI INDIANS. The Hasinai Indians belong to the Caddoan linguistic stock, a large family that includes the Arikara, Pawnee, Wichita, Kitsai, and Caddo Indians. The southern group included the Kadohadachos and Caddos proper, as well as the Nanatsoho, Nasoni, upper Natchitoches, and Cahinnio Indians of Arkansas and, in east Texas, the Hasinais. The last group was composed of eight tribes: Hainai, Neches, Nacogdoche, Nacono (Nacao, Naconish), Namidish, (Nabiti, Nawidish), Nasoni, Anadarko, and perhaps Nabedache. The Hasinais occupied a compact area in the middle Neches and upper Angelina valleys and were seen as the socially most advanced and historically the most important group in the region. The names Texas and Hasinai were used interchangeably. The term Texas or Tejas was the Indian form of greeting which meant "friend." The term Hasinai or its variations (Aseney, Asinai, Asinay, Assinais, or Iones) means "our own people." Today among the descendants of these Caddoan people in Oklahoma the term Hasinai has been revived.

BIBLIOGRAPHY: Herbert E. Bolton, "The Native Tribes about the East Texas Missions," Quarterly of the Texas State Historical Association 11 (April 1908). Frederick Webb Hodge, ed., Handbook of American Indians North of Mexico (2 vols., Washington: GPO, 1907, 1910; rpt., New York: Pageant, 1959). John R. Swanton, Source Material on the History and Ethnology of the Caddo Indians (Smithsonian Institution, Bureau of American Ethnology Bulletin 132, Washington: GPO, 1942).
Thomas N. Campbell