What is "assaji"

Assaji ( Pali:Assaji, Sanskrit:Asvajit) was one of the first five arahants of Gautama Buddha. He is known for his conversion of Sariputta and Mahamoggallana, the Buddha's two chief male disciples, counterparts to the nuns Khema and Uppalavanna, the chief female disciples. He lived in what is now Uttar Pradesh and Bihar in northern India, during the 6th century BCE.