BEN-ONI (bĕn-ō'nī, Heb. ben-’ônî, son of my sorrow). The name given to Benjamin by his dying mother, Rachel (Gen.35.18). See Benjamin.

BEN-ONI bĕn ō’ nī (בֶּנ־אוֹנִ֑י, son of my sorrow). The name which Rachel gave to her son at birth; changed, after her death, to Benjamin by his father, Jacob (Gen 35:18).

International Standard Bible Encyclopedia (1915)

The name given by the dying Rachel to her new-born son; changed by his father Jacob to BENJAMIN (Ge 35:18) which see.