'preapproval' originates from the prefix 'pre-' meaning 'before' and the word 'approval' from Latin 'approbare', where 'ad-' meant 'to' and 'probare' meant 'to test or prove'.

'approbare' transformed into the Old French word 'aprover', and eventually became the modern English word 'approve'.

Initially, it meant 'to test or prove something', but over time it evolved into its current meaning of 'to give consent or agree to something'.