'bacilliparous' originates from New Latin, specifically a compound of Latin 'bacillus' and the suffix '-parous', where 'bacillus' meant 'little rod' (used for rod-shaped bacteria) and '-parous' (from Latin 'parere') meant 'bearing'.

'bacilliparous' was formed in modern scientific coinage by combining the noun 'bacillus' (used in Latin and New Latin for the rod-shaped bacterium) with the adjectival suffix '-parous' (modeled on words like 'viviparous'), producing a term meaning 'bearing bacilli'.

Initially coined to mean 'bearing or producing bacilli' in scientific usage, the term has retained that specialized meaning in modern contexts.