'apocynaceous' ultimately derives from New Latin 'Apocynaceae', the family name based on the genus 'Apocynum'. The genus name comes from Greek 'apó' meaning 'away from' and 'kýōn' (or 'kúon') meaning 'dog'.

The Greek word components formed the genus name 'Apocynum' (used in botanical Latin). From that genus name the family name 'Apocynaceae' was created in New Latin, and the English adjectival form 'apocynaceous' developed in scientific usage to mean 'of or relating to Apocynaceae'.

Originally the name referred to plants (e.g., in the genus Apocynum) reputed to repel or be poisonous to dogs; over time it became a neutral botanical term meaning 'relating to the Apocynaceae family'.