'annonaceous' originates from New Latin 'Annonaceae', specifically the genus name 'Annona', ultimately borrowed from Taíno/Spanish 'anón'/'anona' meaning 'custard apple'.

'annonaceous' was formed in botanical Latin by adding the Latin suffix '-aceus' (via -aceae for family names) to 'Annona' to create 'Annonaceae', and then adapted into English as the adjective 'annonaceous'.

Initially it referred specifically to the genus or family of custard-apple plants; over time it has remained a technical botanical adjective meaning 'of or relating to Annonaceae'.