'anhingas' originates from Tupi (via Portuguese and New Latin), specifically the word 'anhinga', where 'anhinga' meant 'devil bird' or 'snake bird'.

'anhinga' entered New Latin as the genus name 'Anhinga', passed into Portuguese and English common usage, and the English plural 'anhingas' formed regularly in modern English.

Initially, it referred to a 'devil bird/snake bird'; in English it came to denote the birds of the genus 'Anhinga', with 'anhingas' used as the regular plural.