Chipper time.

[Zoom]

a certain masked man was always calling his sidekick "stupid"

This, along with the idea that Tonto was saying (instead of Kemosabe) "Quien no sabe" which means "He who knows nothing", are both urban legends, sadly.

The writers meant "Tonto" to mean "trusty scout", regardless of what it actually meant. And "kemosabe" comes from Camp Kemo Sabe, which was an actual place.