Kemo Sabe is a term that supposedly means "old friend". It comes from a children's television show "The Lone Ranger", in the 1950's and early 1960's. The Lone Ranger was a masked Texas Ranger who traveled with an American Indian companion named Tonto. They did good deeds.
In the show Tonto would call the Lone Ranger "Kemo Sabe".
The show was off the air long ago, but the term "Kemo Sabe" (kee moh sah bay) still survives in the U.S. culture, though it is slowly dying out as memories of the TV show fade.
I'm old enough to remember watching the shows.