'heterogeneously-formed' originates from Greek, specifically the word 'heterogenēs,' where 'hetero-' meant 'different' and 'genēs' meant 'kind or type.'

'heterogenēs' transformed into the Latin word 'heterogeneus,' and eventually became the modern English word 'heterogeneous' through Middle English.

Initially, it meant 'of different kinds,' and this meaning has largely remained the same in modern usage.