Kemosabe (kee-moe-sah-bee) has been defined as both "trusty scout" and "faithful friend."
Radio[]
On the radio show the word Kemosabe is used by both the Lone Ranger and Tonto when referring to the other. In several episodes it seemes to actually be used more by the Ranger than his faithful companion.
Television and Movies[]
On the television show and in the films, Kemosabe became exclusively Tonto's name for the Lone Ranger. Tonto used it everytime he was addressing the Ranger directly.
Notes[]
The word Kemosabe was based on the name of a camp near Detroit. Camp Kemo-Sahbe was near the home of radio producer James Jewell, who said it only ever meant "trusty scout." The "faithful friend" interpretation came later, the circumstances of which are not fully known.