'balaenoidean' originates from New Latin, specifically the word 'Balaenoidea', where the root 'balaena' meant 'whale' (from Latin 'balaena').

'balaenoidean' changed from the New Latin taxonomic name 'Balaenoidea' (formed from Latin 'balaena', itself from Greek 'phálaina' φάλαινα meaning 'whale') and was later adapted into English as the adjective/noun 'balaenoidean'.

Initially associated directly with the taxonomic name meaning 'whale(s)', over time it has come to mean 'relating to or a member of Balaenoidea' in descriptive English usage.