What does the name waco mean?

Although I have no historical or regional knowledge data to substantiate this, I imagine that "waco" is an English language spelling of the Spanish Word "hueco," which would be pronounced identically. The "h" is silent in Spanish and the sound of the following "u" is the phonetic equivalent of "w" in English. "Hueco" in Spanish means "hole, hollow, recess or empty space." The term could also be applied to a well or shaft or any kind of a cavity or depression. Because of the Spanish language heritage of the whole of Texas, the area around Waco may have one or more of the "hueco" attributes, topographically or otherwise, and may have been referred to as the "hueco" by early Spanish speaking inhabitants, and the phonetic reference adopted by later English speakers as "Waco," as Texas passed into the hands of English speakers. If you can't find a better answer, consider this a speculation.