'aquaticness' originates from English formation, ultimately from Latin, specifically the word 'aquaticus,' where 'aqua' meant 'water' and the English suffix '-ness' meant 'state or quality.'

'aquaticus' transformed into French 'aquatique' and then into English 'aquatic'; this combined with the Old English-derived suffix '-ness' to become the modern English word 'aquaticness'.

Initially, it meant 'the state or quality of being aquatic,' and this meaning has remained essentially the same in modern usage.