'unmanned' originates from the prefix 'un-' meaning 'not' and the word 'manned' from Old English 'mann' meaning 'human being'.

'unmanned' changed from the Old English word 'mann' to the modern English word 'manned', with the prefix 'un-' added to denote the absence of humans.

Initially, it meant 'without a man or men', but over time it evolved into its current meaning of 'without a human crew'.