'antrum' originates from Latin, specifically the word 'antrum', where 'antrum' meant 'cave'.

'antrum' changed from Greek 'ἄντρον' (ántron) into Latin as 'antrum' and entered English via Late/Medieval Latin usage, retaining a sense of a hollow or cavity.

Initially it meant 'cave' (a natural hollow), but over time it broadened to refer also to cavities or chambers in anatomy (e.g., maxillary antrum, gastric antrum).