'anthesteria' originates from Ancient Greek, specifically the word 'Ἀνθεστήρια (Anthestēria)', where 'anth-' (from 'ἄνθος, anthos') meant 'flower'.

'anthesteria' was borrowed into English as a classical/scholarly term from Ancient Greek (via Latin or direct classical transcription) to refer to the specific Athenian festival; the form has been used in antiquarian and classical studies literature.

Initially it referred to a 'flowering/flower-feast' (the Greek name evokes blooming), but over time in English it settled as the specific name for the Athenian festival honoring Dionysus and associated rites around new wine.