'Anastomus' originates from Neo-Latin (scientific Latin), ultimately derived from Greek elements: from Greek 'ana-' meaning 'up/again' and 'stoma' meaning 'mouth', combined to indicate an opening or mouth-related feature.

'Anastomus' was formed in modern zoological (Neo-Latin) usage as a genus name in biological classification, borrowing Greek roots and adopted into scientific Latin; it became established in taxonomic literature as the genus name for openbill storks.

Initially the Greek-derived elements referred generally to an 'opening' or 'mouth'; over time the term (as the genus name) came to denote specifically the group of storks characterized by a gap in the bill.