'endogenous' originates from Greek, specifically the word 'endogenēs,' where 'endo-' meant 'within' and '-genēs' meant 'born or produced.'

'endogenēs' was adopted into modern scientific Latin as 'endogenus,' and eventually became the modern English word 'endogenous.'

Initially, it meant 'produced from within,' and this meaning has remained consistent in modern scientific usage.