"Palm isle, the fourth and youngest son of Aaron (1 Chr. 6:3). He" was consecrated to the priesthood along with his brothers (Ex. "6:23); and after the death of Nadab and Abihu, he and Eleazar" "alone discharged the functions of that office (Lev. 10:6, 12;" Num. 3:4). He and his family occupied the position of common priest till the high priesthood passed into his family in the "person of Eli (1 Kings 2:27), the reasons for which are not" recorded. (See [304]ZADOK.)

See where Ithamar occurs in the Bible...

Definition of Ithamar:
"island of the palm-tree"