'entirely' originates from Middle English, specifically the word 'entier', where 'entier' meant 'whole'. 'Clear' originates from Latin, specifically the word 'clarus', where 'clarus' meant 'bright, clear'.

'entier' transformed into the English word 'entire', and 'clarus' transformed into the English word 'clear'.

Initially, 'entirely' meant 'wholly or completely', and 'clear' meant 'bright or transparent'. Over time, 'entirely-clear' evolved to mean 'completely free from ambiguity'.