What does the term, "petty tyrant', mean to Carlos Castenada?

From the text:

“I’m really mystified,” I said. “You keep on saying that la Gorda is the petty tyrant of my life. Just what is a petty tyrant?”

“A petty tyrant is a tormentor,” he replied. “Someone who either holds the power of life and death over warriors or simply annoys them to distraction.”