"The exact origin of the word 'tequil' is unknown and many theories exist that are deeply rooted in cultural myths of the region. Many believe that the word “tequila” comes from the Aztec word téquitl, which means “the place of harvesting.” Others state that the word translates to “Lava Soil” or “The Rock that Cuts,” because the city of Tequila lies within the shadow of a dormant volcano. When the volcano was active, the lava would mix with the sandy soil and heat it up to become molten glass. These black obsidian shards of glass are called 'tequila.'"
"Additionally, it is said that in 1873, the name “tequila” was first used by mezcal producers in the town of Tequila in an attempt to distinguish their product from the mezcal being produced in other parts of Mexico."