'non-aggression' is formed from the prefix 'non-' (from Latin 'non') meaning 'not' combined with 'aggression', which originates from Latin, specifically the word 'aggressio', where 'aggressio' meant 'an attack'.

'aggression' comes from Latin 'aggressio' (from 'aggredi', 'to attack'), passed into Old French as 'agression' and Middle English as forms like 'aggressioun', and eventually became modern English 'aggression'; the prefix 'non-' was attached in modern English to create the compound 'non-aggression'.

Originally, 'aggression' referred to 'an attack' or 'the act of attacking'; over time, the compound 'non-aggression' evolved to mean 'the absence of attack' or 'a policy/agreement of not attacking'.