'aswim' originates from Old English, formed from the prefix 'a-' plus the verb 'swim' (Old English 'swimman'), where 'a-' meant 'on' or 'in the state of' and 'swim' meant 'to move in water'.

'aswim' changed from Middle English forms such as 'aswimmen' (a- + swimmen) and eventually became the modern English word 'aswim'.

Initially it meant 'in a swimming state' or 'on the water', but over time it broadened to mean 'afloat' and figuratively 'awash' or 'abundantly filled'.