'bacilliculture' originates from Latin, specifically the words 'bacillus' and 'cultura', where 'bacillus' meant 'little rod' and 'cultura' meant 'cultivation'.

'bacillus' comes from Latin 'bacillus' (from Greek 'baktron' meaning 'stick, rod'), and 'cultura' comes from Latin 'colere' meaning 'to cultivate'; the compound combining the sense of 'bacillus' + 'culture' developed in scientific/medical English to denote cultivation of rod-shaped bacteria.

Initially it literally meant 'cultivation of little rods (bacilli)', and it has retained that specific technical meaning in microbiological contexts as 'cultivation of bacilli'.