'amiableness' originates from Latin, specifically the word 'amicabilis,' where 'amicus' meant 'friend.'

'amicabilis' transformed into the Old French word 'amiable,' and eventually became the modern English word 'amiable,' with 'amiableness' as its noun form.

Initially, it meant 'friendly or pleasant,' and this meaning has largely remained the same in modern usage.