The term BhunJIA may perhaps signify one who lives on the soil, from bhum, the earth, and JIA, dependent on.
"The Tribes and Castes of the Central Provinces of India Volume II"
R. V. Russell
The word BirJIA, a synonym for Binjhwar, is similarly a corruption of bewar JIA, and means one who is dependent on dahia or patch cultivation.
"The Tribes and Castes of the Central Provinces of India Volume II"
R. V. Russell