The term 'opinion-based' is a compound word formed from 'opinion' and 'based'. 'Opinion' originates from Latin 'opinio', meaning 'belief' or 'judgment', and 'based' comes from the Old French 'basse', meaning 'foundation'.

'Opinion' evolved from the Latin 'opinio' through Old French 'opinion', while 'based' transformed from Old French 'basse' to Middle English 'base'.

Initially, 'opinion' meant 'belief or judgment', and 'based' meant 'foundation'. The compound 'opinion-based' retains the meaning of being founded on personal beliefs.