'endospore' originates from Greek, specifically the word 'endon' meaning 'within' and 'spora' meaning 'seed'.

'endon' and 'spora' combined in scientific Latin to form 'endospora', which eventually became the modern English word 'endospore'.

Initially, it meant 'a seed within', but over time it evolved into its current meaning of 'a resistant spore within bacteria'.