'heterologous' originates from Greek, specifically the word 'heterologos,' where 'hetero-' meant 'different' and 'logos' meant 'relation or word.'

'heterologos' transformed into the Latin word 'heterologus,' and eventually became the modern English word 'heterologous.'

Initially, it meant 'having a different relation,' but over time it evolved into its current meaning of 'derived from a different species or source.'