The story
Coined for the 1938 Lone Ranger television serial. Further etymology uncertain: *Some trace the word through the Kee-Mo Sah-Bee summer camp in Michigan to Ojibwe giimoozaabi (“he spies”). See more at Wikipedia. *Alternatively, from a corruption of Spanish quien lo sabe "(he) who knows".
Etymology from Wiktionary, CC BY-SA 4.0.