'microbiological' originates from 'microbiology', which is derived from the Greek words 'mikros' meaning 'small', 'bios' meaning 'life', and 'logos' meaning 'study'.

'microbiology' evolved from the Greek 'mikros' and 'bios', combined with 'logos', and eventually became the modern English word 'microbiology', leading to the adjective 'microbiological'.

Initially, it referred to the study of small life forms, and this meaning has largely remained the same in modern usage.