What word do they use to describe the converts and what does it mean?

From the text:

None of his converts was a man whose word was heeded in ihe assembly of the people. None of them was a man of title. They were mostly the kind of people that were called efulefu, worthless, empty men. The imagery of an efulefu in the language of the clan was a man who sold his machete and wore the sheath to battle. Chielo, the priestess of Agbala, called the converts the excrement of the clan, and the new faith was a mad dog that had come to eat it up.