kemo sabe, n. — Green’s Dictionary of Slang

kemo sabe n.

[according to scriptwriter Frank Striker, the ‘Native American’ term ‘trusty scout’ applied to the loyal Indian companion, Tonto, in the Lone Ranger radio and television series created by George Trendle in 1933; for some of the alternative theories of the phr. see http://www.write101.com/kemosabe.htm]

(US) a friend, used in direct address.

1933		G. Trendle in Denning Time in Yesterday 368: ‘Years ago you called me “kemo sabe.” ‘That’s right. And you still kemo sabe. It mean “faithful friend”.’ [HDAS].
1986		C. Hiaasen Tourist Season (1987) 75: No, Kemosabe, but I got you a present.
1993		A. Rodriguez Spidertown (1994) 88: Hello there. Kemo sabe. fellow artisan.
2008		T.I. ‘Swing Ya Rag’ 🎵 I say whoa, kimosabe, big ballin is my hobby.