What is "anirvan"

' Anirvan' or Sri Anirvan ( Sri Anirvan) (8 July 1896 – 31 May 1978) born ' Narendra Chandra Dhar' was an Indian/ Bengali/ Hindu monk, writer, Vedic scholar and philosopher. He was widely known as a scholar and his principal works were a Bengali translation of Sri Aurobindo's The Life Divine and the three volume treatise Veda Mimamsa.