'commonly' originates from Middle English, specifically the word 'comunly,' where 'comun' meant 'common.' 'Available' originates from Old French, specifically the word 'avaler,' where 'a-' meant 'to' and 'valoir' meant 'to be worth.'

'commonly' changed from the Middle English word 'comunly' and eventually became the modern English word 'commonly.' 'Available' transformed from the Old French word 'avaler' and eventually became the modern English word 'available.'

Initially, 'commonly' meant 'in a common manner,' and 'available' meant 'to be worth,' but over time they evolved into their current meanings of 'widely accessible' and 'obtainable.'