'non-usurious' originates from English, specifically formed by combining the prefix 'non-' (from Latin via Old French, meaning 'not') with the adjective 'usurious', where 'usurious' derives from Latin 'usura' meaning 'use' or more specifically 'interest charged for use (of money)'.

'non-usurious' is formed by prefixing modern English 'non-' to 'usurious'. The element 'usura' passed into Old French as 'usure', then into Middle English as 'usury' (meaning charged interest), which with the suffix '-ous' produced 'usurious' in Early Modern English; the modern compound 'non-usurious' is created by adding the productive prefix 'non-'.

Initially the Latin root 'usura' referred generally to 'use' or 'the act of using'; over time it narrowed to mean 'interest (paid for the use of money)' and later to the sense of excessive or illegal interest ('usury'). 'Usurious' came to mean 'relating to excessive interest', and 'non-usurious' now means 'not involving such excessive interest'.