Githyanki call those who are trained in both fighting and spellcasting gish, meaning "skilled." These talented individuals are rare and well-respected, often becoming leaders or other people of influence. Gish include fighter/wizards, barbarian sorcerers, monk/psions, bards, and psychic warriors.
A gish who serves as the Sarth of a unit is called a gish'sarath. A gish who serves as the captain carries the formal title of gish'kith'arak.
A Guide to the Astral Plane, page 50
Polyhedron #159, page 27 (included with Dungeon #100)