'non-threatening' originates from the prefix 'non-' meaning 'not' and the word 'threatening', which comes from the Old English 'þreatian', meaning 'to press or urge'.

'þreatian' transformed into the Middle English word 'threten', and eventually became the modern English word 'threaten'.

Initially, 'threaten' meant 'to press or urge', but over time it evolved into its current meaning of 'to express a threat'.