'antiusurious' originates from Modern English, specifically the combination of the prefix 'anti-' (from Greek 'anti') and the adjective 'usurious' (from Latin 'usura' via Old French), where 'anti-' meant 'against' and 'usura' meant 'use, interest'.

'antiusurious' was formed in Modern English by combining the prefix 'anti-' with 'usurious'. 'Usurious' itself developed from Middle English 'usuriouse' (from Old French 'usurie' / 'usurieux') ultimately from Latin 'usura' meaning 'use, interest'. Over time these elements combined to produce the modern compound adjective.

Initially, the root 'usura' referred broadly to 'use' or 'the act of using' and then came to mean 'interest charged on a loan'; over time 'usury' acquired a negative sense of excessive or unlawful interest, and 'antiusurious' now denotes opposition to such excessive interest.