What is "mahanayaka"

Mahanayaka (also spelled as Maha Nayaka, Maha Nayake) theros are high-ranking Buddhist monks who oversees and regulates the Buddhist clergy in Theravada Buddhist countries. The title Maha Nayaka translates to English as 'Great Leader' and it is considered to be a very important position held by a monk in a Theravada Buddhist country. It is usually bestowed upon the senior Buddhist monks who are appointed as the chief prelates of monastic fraternities known as Nikayas.