'deliciousness' originates from Late Latin, specifically the adjective 'deliciōsus', where the noun 'deliciae' meant 'delights' or 'pleasures'.

'deliciousness' changed from Late Latin 'deliciōsus' into Old French 'delicieux' (or Middle French 'délicieux'), then into Middle English 'delicious', and eventually became the modern English noun 'deliciousness'.

Initially, it meant 'full of delight' or 'causing delight', but over time it narrowed to its current meaning of 'the quality of being pleasant to taste'.